Fix dupplicate declaration of ggc_realloc in gencondmd
[official-gcc.git] / gcc / ada / exp_aggr.adb
blob60838de36740ad0d343290ddd9e12537be217295
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- E X P _ A G G R --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2014, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Expander; use Expander;
33 with Exp_Util; use Exp_Util;
34 with Exp_Ch3; use Exp_Ch3;
35 with Exp_Ch6; use Exp_Ch6;
36 with Exp_Ch7; use Exp_Ch7;
37 with Exp_Ch9; use Exp_Ch9;
38 with Exp_Disp; use Exp_Disp;
39 with Exp_Tss; use Exp_Tss;
40 with Fname; use Fname;
41 with Freeze; use Freeze;
42 with Itypes; use Itypes;
43 with Lib; use Lib;
44 with Namet; use Namet;
45 with Nmake; use Nmake;
46 with Nlists; use Nlists;
47 with Opt; use Opt;
48 with Restrict; use Restrict;
49 with Rident; use Rident;
50 with Rtsfind; use Rtsfind;
51 with Ttypes; use Ttypes;
52 with Sem; use Sem;
53 with Sem_Aggr; use Sem_Aggr;
54 with Sem_Aux; use Sem_Aux;
55 with Sem_Ch3; use Sem_Ch3;
56 with Sem_Eval; use Sem_Eval;
57 with Sem_Res; use Sem_Res;
58 with Sem_Util; use Sem_Util;
59 with Sinfo; use Sinfo;
60 with Snames; use Snames;
61 with Stand; use Stand;
62 with Stringt; use Stringt;
63 with Targparm; use Targparm;
64 with Tbuild; use Tbuild;
65 with Uintp; use Uintp;
67 package body Exp_Aggr is
69 type Case_Bounds is record
70 Choice_Lo : Node_Id;
71 Choice_Hi : Node_Id;
72 Choice_Node : Node_Id;
73 end record;
75 type Case_Table_Type is array (Nat range <>) of Case_Bounds;
76 -- Table type used by Check_Case_Choices procedure
78 procedure Collect_Initialization_Statements
79 (Obj : Entity_Id;
80 N : Node_Id;
81 Node_After : Node_Id);
82 -- If Obj is not frozen, collect actions inserted after N until, but not
83 -- including, Node_After, for initialization of Obj, and move them to an
84 -- expression with actions, which becomes the Initialization_Statements for
85 -- Obj.
87 function Has_Default_Init_Comps (N : Node_Id) return Boolean;
88 -- N is an aggregate (record or array). Checks the presence of default
89 -- initialization (<>) in any component (Ada 2005: AI-287).
91 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean;
92 -- Returns true if N is an aggregate used to initialize the components
93 -- of a statically allocated dispatch table.
95 function Must_Slide
96 (Obj_Type : Entity_Id;
97 Typ : Entity_Id) return Boolean;
98 -- A static array aggregate in an object declaration can in most cases be
99 -- expanded in place. The one exception is when the aggregate is given
100 -- with component associations that specify different bounds from those of
101 -- the type definition in the object declaration. In this pathological
102 -- case the aggregate must slide, and we must introduce an intermediate
103 -- temporary to hold it.
105 -- The same holds in an assignment to one-dimensional array of arrays,
106 -- when a component may be given with bounds that differ from those of the
107 -- component type.
109 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type);
110 -- Sort the Case Table using the Lower Bound of each Choice as the key.
111 -- A simple insertion sort is used since the number of choices in a case
112 -- statement of variant part will usually be small and probably in near
113 -- sorted order.
115 ------------------------------------------------------
116 -- Local subprograms for Record Aggregate Expansion --
117 ------------------------------------------------------
119 function Build_Record_Aggr_Code
120 (N : Node_Id;
121 Typ : Entity_Id;
122 Lhs : Node_Id) return List_Id;
123 -- N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the
124 -- aggregate. Target is an expression containing the location on which the
125 -- component by component assignments will take place. Returns the list of
126 -- assignments plus all other adjustments needed for tagged and controlled
127 -- types.
129 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id);
130 -- N is an N_Aggregate or an N_Extension_Aggregate. Typ is the type of the
131 -- aggregate (which can only be a record type, this procedure is only used
132 -- for record types). Transform the given aggregate into a sequence of
133 -- assignments performed component by component.
135 procedure Expand_Record_Aggregate
136 (N : Node_Id;
137 Orig_Tag : Node_Id := Empty;
138 Parent_Expr : Node_Id := Empty);
139 -- This is the top level procedure for record aggregate expansion.
140 -- Expansion for record aggregates needs expand aggregates for tagged
141 -- record types. Specifically Expand_Record_Aggregate adds the Tag
142 -- field in front of the Component_Association list that was created
143 -- during resolution by Resolve_Record_Aggregate.
145 -- N is the record aggregate node.
146 -- Orig_Tag is the value of the Tag that has to be provided for this
147 -- specific aggregate. It carries the tag corresponding to the type
148 -- of the outermost aggregate during the recursive expansion
149 -- Parent_Expr is the ancestor part of the original extension
150 -- aggregate
152 function Has_Mutable_Components (Typ : Entity_Id) return Boolean;
153 -- Return true if one of the components is of a discriminated type with
154 -- defaults. An aggregate for a type with mutable components must be
155 -- expanded into individual assignments.
157 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id);
158 -- If the type of the aggregate is a type extension with renamed discrimi-
159 -- nants, we must initialize the hidden discriminants of the parent.
160 -- Otherwise, the target object must not be initialized. The discriminants
161 -- are initialized by calling the initialization procedure for the type.
162 -- This is incorrect if the initialization of other components has any
163 -- side effects. We restrict this call to the case where the parent type
164 -- has a variant part, because this is the only case where the hidden
165 -- discriminants are accessed, namely when calling discriminant checking
166 -- functions of the parent type, and when applying a stream attribute to
167 -- an object of the derived type.
169 -----------------------------------------------------
170 -- Local Subprograms for Array Aggregate Expansion --
171 -----------------------------------------------------
173 function Aggr_Size_OK (N : Node_Id; Typ : Entity_Id) return Boolean;
174 -- Very large static aggregates present problems to the back-end, and are
175 -- transformed into assignments and loops. This function verifies that the
176 -- total number of components of an aggregate is acceptable for rewriting
177 -- into a purely positional static form. Aggr_Size_OK must be called before
178 -- calling Flatten.
180 -- This function also detects and warns about one-component aggregates that
181 -- appear in a non-static context. Even if the component value is static,
182 -- such an aggregate must be expanded into an assignment.
184 function Backend_Processing_Possible (N : Node_Id) return Boolean;
185 -- This function checks if array aggregate N can be processed directly
186 -- by the backend. If this is the case, True is returned.
188 function Build_Array_Aggr_Code
189 (N : Node_Id;
190 Ctype : Entity_Id;
191 Index : Node_Id;
192 Into : Node_Id;
193 Scalar_Comp : Boolean;
194 Indexes : List_Id := No_List) return List_Id;
195 -- This recursive routine returns a list of statements containing the
196 -- loops and assignments that are needed for the expansion of the array
197 -- aggregate N.
199 -- N is the (sub-)aggregate node to be expanded into code. This node has
200 -- been fully analyzed, and its Etype is properly set.
202 -- Index is the index node corresponding to the array sub-aggregate N
204 -- Into is the target expression into which we are copying the aggregate.
205 -- Note that this node may not have been analyzed yet, and so the Etype
206 -- field may not be set.
208 -- Scalar_Comp is True if the component type of the aggregate is scalar
210 -- Indexes is the current list of expressions used to index the object we
211 -- are writing into.
213 procedure Convert_Array_Aggr_In_Allocator
214 (Decl : Node_Id;
215 Aggr : Node_Id;
216 Target : Node_Id);
217 -- If the aggregate appears within an allocator and can be expanded in
218 -- place, this routine generates the individual assignments to components
219 -- of the designated object. This is an optimization over the general
220 -- case, where a temporary is first created on the stack and then used to
221 -- construct the allocated object on the heap.
223 procedure Convert_To_Positional
224 (N : Node_Id;
225 Max_Others_Replicate : Nat := 5;
226 Handle_Bit_Packed : Boolean := False);
227 -- If possible, convert named notation to positional notation. This
228 -- conversion is possible only in some static cases. If the conversion is
229 -- possible, then N is rewritten with the analyzed converted aggregate.
230 -- The parameter Max_Others_Replicate controls the maximum number of
231 -- values corresponding to an others choice that will be converted to
232 -- positional notation (the default of 5 is the normal limit, and reflects
233 -- the fact that normally the loop is better than a lot of separate
234 -- assignments). Note that this limit gets overridden in any case if
235 -- either of the restrictions No_Elaboration_Code or No_Implicit_Loops is
236 -- set. The parameter Handle_Bit_Packed is usually set False (since we do
237 -- not expect the back end to handle bit packed arrays, so the normal case
238 -- of conversion is pointless), but in the special case of a call from
239 -- Packed_Array_Aggregate_Handled, we set this parameter to True, since
240 -- these are cases we handle in there.
242 -- It would seem worthwhile to have a higher default value for Max_Others_
243 -- replicate, but aggregates in the compiler make this impossible: the
244 -- compiler bootstrap fails if Max_Others_Replicate is greater than 25.
245 -- This is unexpected ???
247 procedure Expand_Array_Aggregate (N : Node_Id);
248 -- This is the top-level routine to perform array aggregate expansion.
249 -- N is the N_Aggregate node to be expanded.
251 function Is_Two_Dim_Packed_Array (Typ : Entity_Id) return Boolean;
252 -- For two-dimensional packed aggregates with constant bounds and constant
253 -- components, it is preferable to pack the inner aggregates because the
254 -- whole matrix can then be presented to the back-end as a one-dimensional
255 -- list of literals. This is much more efficient than expanding into single
256 -- component assignments. This function determines if the type Typ is for
257 -- an array that is suitable for this optimization: it returns True if Typ
258 -- is a two dimensional bit packed array with component size 1, 2, or 4.
260 function Late_Expansion
261 (N : Node_Id;
262 Typ : Entity_Id;
263 Target : Node_Id) return List_Id;
264 -- This routine implements top-down expansion of nested aggregates. In
265 -- doing so, it avoids the generation of temporaries at each level. N is
266 -- a nested record or array aggregate with the Expansion_Delayed flag.
267 -- Typ is the expected type of the aggregate. Target is a (duplicatable)
268 -- expression that will hold the result of the aggregate expansion.
270 function Make_OK_Assignment_Statement
271 (Sloc : Source_Ptr;
272 Name : Node_Id;
273 Expression : Node_Id) return Node_Id;
274 -- This is like Make_Assignment_Statement, except that Assignment_OK
275 -- is set in the left operand. All assignments built by this unit use
276 -- this routine. This is needed to deal with assignments to initialized
277 -- constants that are done in place.
279 function Number_Of_Choices (N : Node_Id) return Nat;
280 -- Returns the number of discrete choices (not including the others choice
281 -- if present) contained in (sub-)aggregate N.
283 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean;
284 -- Given an array aggregate, this function handles the case of a packed
285 -- array aggregate with all constant values, where the aggregate can be
286 -- evaluated at compile time. If this is possible, then N is rewritten
287 -- to be its proper compile time value with all the components properly
288 -- assembled. The expression is analyzed and resolved and True is returned.
289 -- If this transformation is not possible, N is unchanged and False is
290 -- returned.
292 function Two_Dim_Packed_Array_Handled (N : Node_Id) return Boolean;
293 -- If the type of the aggregate is a two-dimensional bit_packed array
294 -- it may be transformed into an array of bytes with constant values,
295 -- and presented to the back-end as a static value. The function returns
296 -- false if this transformation cannot be performed. THis is similar to,
297 -- and reuses part of the machinery in Packed_Array_Aggregate_Handled.
299 ------------------
300 -- Aggr_Size_OK --
301 ------------------
303 function Aggr_Size_OK (N : Node_Id; Typ : Entity_Id) return Boolean is
304 Lo : Node_Id;
305 Hi : Node_Id;
306 Indx : Node_Id;
307 Siz : Int;
308 Lov : Uint;
309 Hiv : Uint;
311 Max_Aggr_Size : Nat;
312 -- Determines the maximum size of an array aggregate produced by
313 -- converting named to positional notation (e.g. from others clauses).
314 -- This avoids running away with attempts to convert huge aggregates,
315 -- which hit memory limits in the backend.
317 function Component_Count (T : Entity_Id) return Int;
318 -- The limit is applied to the total number of components that the
319 -- aggregate will have, which is the number of static expressions
320 -- that will appear in the flattened array. This requires a recursive
321 -- computation of the number of scalar components of the structure.
323 ---------------------
324 -- Component_Count --
325 ---------------------
327 function Component_Count (T : Entity_Id) return Int is
328 Res : Int := 0;
329 Comp : Entity_Id;
331 begin
332 if Is_Scalar_Type (T) then
333 return 1;
335 elsif Is_Record_Type (T) then
336 Comp := First_Component (T);
337 while Present (Comp) loop
338 Res := Res + Component_Count (Etype (Comp));
339 Next_Component (Comp);
340 end loop;
342 return Res;
344 elsif Is_Array_Type (T) then
345 declare
346 Lo : constant Node_Id :=
347 Type_Low_Bound (Etype (First_Index (T)));
348 Hi : constant Node_Id :=
349 Type_High_Bound (Etype (First_Index (T)));
351 Siz : constant Int := Component_Count (Component_Type (T));
353 begin
354 if not Compile_Time_Known_Value (Lo)
355 or else not Compile_Time_Known_Value (Hi)
356 then
357 return 0;
358 else
359 return
360 Siz * UI_To_Int (Expr_Value (Hi) - Expr_Value (Lo) + 1);
361 end if;
362 end;
364 else
365 -- Can only be a null for an access type
367 return 1;
368 end if;
369 end Component_Count;
371 -- Start of processing for Aggr_Size_OK
373 begin
374 -- The normal aggregate limit is 50000, but we increase this limit to
375 -- 2**24 (about 16 million) if Restrictions (No_Elaboration_Code) or
376 -- Restrictions (No_Implicit_Loops) is specified, since in either case
377 -- we are at risk of declaring the program illegal because of this
378 -- limit. We also increase the limit when Static_Elaboration_Desired,
379 -- given that this means that objects are intended to be placed in data
380 -- memory.
382 -- We also increase the limit if the aggregate is for a packed two-
383 -- dimensional array, because if components are static it is much more
384 -- efficient to construct a one-dimensional equivalent array with static
385 -- components.
387 -- Conversely, we decrease the maximum size if none of the above
388 -- requirements apply, and if the aggregate has a single component
389 -- association, which will be more efficient if implemented with a loop.
391 -- Finally, we use a small limit in CodePeer mode where we favor loops
392 -- instead of thousands of single assignments (from large aggregates).
394 Max_Aggr_Size := 50000;
396 if CodePeer_Mode then
397 Max_Aggr_Size := 100;
399 elsif Restriction_Active (No_Elaboration_Code)
400 or else Restriction_Active (No_Implicit_Loops)
401 or else Is_Two_Dim_Packed_Array (Typ)
402 or else (Ekind (Current_Scope) = E_Package
403 and then Static_Elaboration_Desired (Current_Scope))
404 then
405 Max_Aggr_Size := 2 ** 24;
407 elsif No (Expressions (N))
408 and then No (Next (First (Component_Associations (N))))
409 then
410 Max_Aggr_Size := 5000;
411 end if;
413 Siz := Component_Count (Component_Type (Typ));
415 Indx := First_Index (Typ);
416 while Present (Indx) loop
417 Lo := Type_Low_Bound (Etype (Indx));
418 Hi := Type_High_Bound (Etype (Indx));
420 -- Bounds need to be known at compile time
422 if not Compile_Time_Known_Value (Lo)
423 or else not Compile_Time_Known_Value (Hi)
424 then
425 return False;
426 end if;
428 Lov := Expr_Value (Lo);
429 Hiv := Expr_Value (Hi);
431 -- A flat array is always safe
433 if Hiv < Lov then
434 return True;
435 end if;
437 -- One-component aggregates are suspicious, and if the context type
438 -- is an object declaration with non-static bounds it will trip gcc;
439 -- such an aggregate must be expanded into a single assignment.
441 if Hiv = Lov and then Nkind (Parent (N)) = N_Object_Declaration then
442 declare
443 Index_Type : constant Entity_Id :=
444 Etype
445 (First_Index (Etype (Defining_Identifier (Parent (N)))));
446 Indx : Node_Id;
448 begin
449 if not Compile_Time_Known_Value (Type_Low_Bound (Index_Type))
450 or else not Compile_Time_Known_Value
451 (Type_High_Bound (Index_Type))
452 then
453 if Present (Component_Associations (N)) then
454 Indx :=
455 First (Choices (First (Component_Associations (N))));
457 if Is_Entity_Name (Indx)
458 and then not Is_Type (Entity (Indx))
459 then
460 Error_Msg_N
461 ("single component aggregate in "
462 & "non-static context??", Indx);
463 Error_Msg_N ("\maybe subtype name was meant??", Indx);
464 end if;
465 end if;
467 return False;
468 end if;
469 end;
470 end if;
472 declare
473 Rng : constant Uint := Hiv - Lov + 1;
475 begin
476 -- Check if size is too large
478 if not UI_Is_In_Int_Range (Rng) then
479 return False;
480 end if;
482 Siz := Siz * UI_To_Int (Rng);
483 end;
485 if Siz <= 0
486 or else Siz > Max_Aggr_Size
487 then
488 return False;
489 end if;
491 -- Bounds must be in integer range, for later array construction
493 if not UI_Is_In_Int_Range (Lov)
494 or else
495 not UI_Is_In_Int_Range (Hiv)
496 then
497 return False;
498 end if;
500 Next_Index (Indx);
501 end loop;
503 return True;
504 end Aggr_Size_OK;
506 ---------------------------------
507 -- Backend_Processing_Possible --
508 ---------------------------------
510 -- Backend processing by Gigi/gcc is possible only if all the following
511 -- conditions are met:
513 -- 1. N is fully positional
515 -- 2. N is not a bit-packed array aggregate;
517 -- 3. The size of N's array type must be known at compile time. Note
518 -- that this implies that the component size is also known
520 -- 4. The array type of N does not follow the Fortran layout convention
521 -- or if it does it must be 1 dimensional.
523 -- 5. The array component type may not be tagged (which could necessitate
524 -- reassignment of proper tags).
526 -- 6. The array component type must not have unaligned bit components
528 -- 7. None of the components of the aggregate may be bit unaligned
529 -- components.
531 -- 8. There cannot be delayed components, since we do not know enough
532 -- at this stage to know if back end processing is possible.
534 -- 9. There cannot be any discriminated record components, since the
535 -- back end cannot handle this complex case.
537 -- 10. No controlled actions need to be generated for components
539 -- 11. For a VM back end, the array should have no aliased components
541 function Backend_Processing_Possible (N : Node_Id) return Boolean is
542 Typ : constant Entity_Id := Etype (N);
543 -- Typ is the correct constrained array subtype of the aggregate
545 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean;
546 -- This routine checks components of aggregate N, enforcing checks
547 -- 1, 7, 8, and 9. In the multi-dimensional case, these checks are
548 -- performed on subaggregates. The Index value is the current index
549 -- being checked in the multi-dimensional case.
551 ---------------------
552 -- Component_Check --
553 ---------------------
555 function Component_Check (N : Node_Id; Index : Node_Id) return Boolean is
556 Expr : Node_Id;
558 begin
559 -- Checks 1: (no component associations)
561 if Present (Component_Associations (N)) then
562 return False;
563 end if;
565 -- Checks on components
567 -- Recurse to check subaggregates, which may appear in qualified
568 -- expressions. If delayed, the front-end will have to expand.
569 -- If the component is a discriminated record, treat as non-static,
570 -- as the back-end cannot handle this properly.
572 Expr := First (Expressions (N));
573 while Present (Expr) loop
575 -- Checks 8: (no delayed components)
577 if Is_Delayed_Aggregate (Expr) then
578 return False;
579 end if;
581 -- Checks 9: (no discriminated records)
583 if Present (Etype (Expr))
584 and then Is_Record_Type (Etype (Expr))
585 and then Has_Discriminants (Etype (Expr))
586 then
587 return False;
588 end if;
590 -- Checks 7. Component must not be bit aligned component
592 if Possible_Bit_Aligned_Component (Expr) then
593 return False;
594 end if;
596 -- Recursion to following indexes for multiple dimension case
598 if Present (Next_Index (Index))
599 and then not Component_Check (Expr, Next_Index (Index))
600 then
601 return False;
602 end if;
604 -- All checks for that component finished, on to next
606 Next (Expr);
607 end loop;
609 return True;
610 end Component_Check;
612 -- Start of processing for Backend_Processing_Possible
614 begin
615 -- Checks 2 (array not bit packed) and 10 (no controlled actions)
617 if Is_Bit_Packed_Array (Typ) or else Needs_Finalization (Typ) then
618 return False;
619 end if;
621 -- If component is limited, aggregate must be expanded because each
622 -- component assignment must be built in place.
624 if Is_Limited_View (Component_Type (Typ)) then
625 return False;
626 end if;
628 -- Checks 4 (array must not be multi-dimensional Fortran case)
630 if Convention (Typ) = Convention_Fortran
631 and then Number_Dimensions (Typ) > 1
632 then
633 return False;
634 end if;
636 -- Checks 3 (size of array must be known at compile time)
638 if not Size_Known_At_Compile_Time (Typ) then
639 return False;
640 end if;
642 -- Checks on components
644 if not Component_Check (N, First_Index (Typ)) then
645 return False;
646 end if;
648 -- Checks 5 (if the component type is tagged, then we may need to do
649 -- tag adjustments. Perhaps this should be refined to check for any
650 -- component associations that actually need tag adjustment, similar
651 -- to the test in Component_Not_OK_For_Backend for record aggregates
652 -- with tagged components, but not clear whether it's worthwhile ???;
653 -- in the case of the JVM, object tags are handled implicitly)
655 if Is_Tagged_Type (Component_Type (Typ))
656 and then Tagged_Type_Expansion
657 then
658 return False;
659 end if;
661 -- Checks 6 (component type must not have bit aligned components)
663 if Type_May_Have_Bit_Aligned_Components (Component_Type (Typ)) then
664 return False;
665 end if;
667 -- Checks 11: Array aggregates with aliased components are currently
668 -- not well supported by the VM backend; disable temporarily this
669 -- backend processing until it is definitely supported.
671 if VM_Target /= No_VM
672 and then Has_Aliased_Components (Base_Type (Typ))
673 then
674 return False;
675 end if;
677 -- Backend processing is possible
679 Set_Size_Known_At_Compile_Time (Etype (N), True);
680 return True;
681 end Backend_Processing_Possible;
683 ---------------------------
684 -- Build_Array_Aggr_Code --
685 ---------------------------
687 -- The code that we generate from a one dimensional aggregate is
689 -- 1. If the sub-aggregate contains discrete choices we
691 -- (a) Sort the discrete choices
693 -- (b) Otherwise for each discrete choice that specifies a range we
694 -- emit a loop. If a range specifies a maximum of three values, or
695 -- we are dealing with an expression we emit a sequence of
696 -- assignments instead of a loop.
698 -- (c) Generate the remaining loops to cover the others choice if any
700 -- 2. If the aggregate contains positional elements we
702 -- (a) translate the positional elements in a series of assignments
704 -- (b) Generate a final loop to cover the others choice if any.
705 -- Note that this final loop has to be a while loop since the case
707 -- L : Integer := Integer'Last;
708 -- H : Integer := Integer'Last;
709 -- A : array (L .. H) := (1, others =>0);
711 -- cannot be handled by a for loop. Thus for the following
713 -- array (L .. H) := (.. positional elements.., others =>E);
715 -- we always generate something like:
717 -- J : Index_Type := Index_Of_Last_Positional_Element;
718 -- while J < H loop
719 -- J := Index_Base'Succ (J)
720 -- Tmp (J) := E;
721 -- end loop;
723 function Build_Array_Aggr_Code
724 (N : Node_Id;
725 Ctype : Entity_Id;
726 Index : Node_Id;
727 Into : Node_Id;
728 Scalar_Comp : Boolean;
729 Indexes : List_Id := No_List) return List_Id
731 Loc : constant Source_Ptr := Sloc (N);
732 Index_Base : constant Entity_Id := Base_Type (Etype (Index));
733 Index_Base_L : constant Node_Id := Type_Low_Bound (Index_Base);
734 Index_Base_H : constant Node_Id := Type_High_Bound (Index_Base);
736 function Add (Val : Int; To : Node_Id) return Node_Id;
737 -- Returns an expression where Val is added to expression To, unless
738 -- To+Val is provably out of To's base type range. To must be an
739 -- already analyzed expression.
741 function Empty_Range (L, H : Node_Id) return Boolean;
742 -- Returns True if the range defined by L .. H is certainly empty
744 function Equal (L, H : Node_Id) return Boolean;
745 -- Returns True if L = H for sure
747 function Index_Base_Name return Node_Id;
748 -- Returns a new reference to the index type name
750 function Gen_Assign (Ind : Node_Id; Expr : Node_Id) return List_Id;
751 -- Ind must be a side-effect free expression. If the input aggregate
752 -- N to Build_Loop contains no sub-aggregates, then this function
753 -- returns the assignment statement:
755 -- Into (Indexes, Ind) := Expr;
757 -- Otherwise we call Build_Code recursively
759 -- Ada 2005 (AI-287): In case of default initialized component, Expr
760 -- is empty and we generate a call to the corresponding IP subprogram.
762 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id;
763 -- Nodes L and H must be side-effect free expressions.
764 -- If the input aggregate N to Build_Loop contains no sub-aggregates,
765 -- This routine returns the for loop statement
767 -- for J in Index_Base'(L) .. Index_Base'(H) loop
768 -- Into (Indexes, J) := Expr;
769 -- end loop;
771 -- Otherwise we call Build_Code recursively.
772 -- As an optimization if the loop covers 3 or less scalar elements we
773 -- generate a sequence of assignments.
775 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id;
776 -- Nodes L and H must be side-effect free expressions.
777 -- If the input aggregate N to Build_Loop contains no sub-aggregates,
778 -- This routine returns the while loop statement
780 -- J : Index_Base := L;
781 -- while J < H loop
782 -- J := Index_Base'Succ (J);
783 -- Into (Indexes, J) := Expr;
784 -- end loop;
786 -- Otherwise we call Build_Code recursively
788 function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean;
789 function Local_Expr_Value (E : Node_Id) return Uint;
790 -- These two Local routines are used to replace the corresponding ones
791 -- in sem_eval because while processing the bounds of an aggregate with
792 -- discrete choices whose index type is an enumeration, we build static
793 -- expressions not recognized by Compile_Time_Known_Value as such since
794 -- they have not yet been analyzed and resolved. All the expressions in
795 -- question are things like Index_Base_Name'Val (Const) which we can
796 -- easily recognize as being constant.
798 ---------
799 -- Add --
800 ---------
802 function Add (Val : Int; To : Node_Id) return Node_Id is
803 Expr_Pos : Node_Id;
804 Expr : Node_Id;
805 To_Pos : Node_Id;
806 U_To : Uint;
807 U_Val : constant Uint := UI_From_Int (Val);
809 begin
810 -- Note: do not try to optimize the case of Val = 0, because
811 -- we need to build a new node with the proper Sloc value anyway.
813 -- First test if we can do constant folding
815 if Local_Compile_Time_Known_Value (To) then
816 U_To := Local_Expr_Value (To) + Val;
818 -- Determine if our constant is outside the range of the index.
819 -- If so return an Empty node. This empty node will be caught
820 -- by Empty_Range below.
822 if Compile_Time_Known_Value (Index_Base_L)
823 and then U_To < Expr_Value (Index_Base_L)
824 then
825 return Empty;
827 elsif Compile_Time_Known_Value (Index_Base_H)
828 and then U_To > Expr_Value (Index_Base_H)
829 then
830 return Empty;
831 end if;
833 Expr_Pos := Make_Integer_Literal (Loc, U_To);
834 Set_Is_Static_Expression (Expr_Pos);
836 if not Is_Enumeration_Type (Index_Base) then
837 Expr := Expr_Pos;
839 -- If we are dealing with enumeration return
840 -- Index_Base'Val (Expr_Pos)
842 else
843 Expr :=
844 Make_Attribute_Reference
845 (Loc,
846 Prefix => Index_Base_Name,
847 Attribute_Name => Name_Val,
848 Expressions => New_List (Expr_Pos));
849 end if;
851 return Expr;
852 end if;
854 -- If we are here no constant folding possible
856 if not Is_Enumeration_Type (Index_Base) then
857 Expr :=
858 Make_Op_Add (Loc,
859 Left_Opnd => Duplicate_Subexpr (To),
860 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
862 -- If we are dealing with enumeration return
863 -- Index_Base'Val (Index_Base'Pos (To) + Val)
865 else
866 To_Pos :=
867 Make_Attribute_Reference
868 (Loc,
869 Prefix => Index_Base_Name,
870 Attribute_Name => Name_Pos,
871 Expressions => New_List (Duplicate_Subexpr (To)));
873 Expr_Pos :=
874 Make_Op_Add (Loc,
875 Left_Opnd => To_Pos,
876 Right_Opnd => Make_Integer_Literal (Loc, U_Val));
878 Expr :=
879 Make_Attribute_Reference
880 (Loc,
881 Prefix => Index_Base_Name,
882 Attribute_Name => Name_Val,
883 Expressions => New_List (Expr_Pos));
884 end if;
886 return Expr;
887 end Add;
889 -----------------
890 -- Empty_Range --
891 -----------------
893 function Empty_Range (L, H : Node_Id) return Boolean is
894 Is_Empty : Boolean := False;
895 Low : Node_Id;
896 High : Node_Id;
898 begin
899 -- First check if L or H were already detected as overflowing the
900 -- index base range type by function Add above. If this is so Add
901 -- returns the empty node.
903 if No (L) or else No (H) then
904 return True;
905 end if;
907 for J in 1 .. 3 loop
908 case J is
910 -- L > H range is empty
912 when 1 =>
913 Low := L;
914 High := H;
916 -- B_L > H range must be empty
918 when 2 =>
919 Low := Index_Base_L;
920 High := H;
922 -- L > B_H range must be empty
924 when 3 =>
925 Low := L;
926 High := Index_Base_H;
927 end case;
929 if Local_Compile_Time_Known_Value (Low)
930 and then
931 Local_Compile_Time_Known_Value (High)
932 then
933 Is_Empty :=
934 UI_Gt (Local_Expr_Value (Low), Local_Expr_Value (High));
935 end if;
937 exit when Is_Empty;
938 end loop;
940 return Is_Empty;
941 end Empty_Range;
943 -----------
944 -- Equal --
945 -----------
947 function Equal (L, H : Node_Id) return Boolean is
948 begin
949 if L = H then
950 return True;
952 elsif Local_Compile_Time_Known_Value (L)
953 and then
954 Local_Compile_Time_Known_Value (H)
955 then
956 return UI_Eq (Local_Expr_Value (L), Local_Expr_Value (H));
957 end if;
959 return False;
960 end Equal;
962 ----------------
963 -- Gen_Assign --
964 ----------------
966 function Gen_Assign (Ind : Node_Id; Expr : Node_Id) return List_Id is
967 L : constant List_Id := New_List;
968 A : Node_Id;
970 New_Indexes : List_Id;
971 Indexed_Comp : Node_Id;
972 Expr_Q : Node_Id;
973 Comp_Type : Entity_Id := Empty;
975 function Add_Loop_Actions (Lis : List_Id) return List_Id;
976 -- Collect insert_actions generated in the construction of a
977 -- loop, and prepend them to the sequence of assignments to
978 -- complete the eventual body of the loop.
980 ----------------------
981 -- Add_Loop_Actions --
982 ----------------------
984 function Add_Loop_Actions (Lis : List_Id) return List_Id is
985 Res : List_Id;
987 begin
988 -- Ada 2005 (AI-287): Do nothing else in case of default
989 -- initialized component.
991 if No (Expr) then
992 return Lis;
994 elsif Nkind (Parent (Expr)) = N_Component_Association
995 and then Present (Loop_Actions (Parent (Expr)))
996 then
997 Append_List (Lis, Loop_Actions (Parent (Expr)));
998 Res := Loop_Actions (Parent (Expr));
999 Set_Loop_Actions (Parent (Expr), No_List);
1000 return Res;
1002 else
1003 return Lis;
1004 end if;
1005 end Add_Loop_Actions;
1007 -- Start of processing for Gen_Assign
1009 begin
1010 if No (Indexes) then
1011 New_Indexes := New_List;
1012 else
1013 New_Indexes := New_Copy_List_Tree (Indexes);
1014 end if;
1016 Append_To (New_Indexes, Ind);
1018 if Present (Next_Index (Index)) then
1019 return
1020 Add_Loop_Actions (
1021 Build_Array_Aggr_Code
1022 (N => Expr,
1023 Ctype => Ctype,
1024 Index => Next_Index (Index),
1025 Into => Into,
1026 Scalar_Comp => Scalar_Comp,
1027 Indexes => New_Indexes));
1028 end if;
1030 -- If we get here then we are at a bottom-level (sub-)aggregate
1032 Indexed_Comp :=
1033 Checks_Off
1034 (Make_Indexed_Component (Loc,
1035 Prefix => New_Copy_Tree (Into),
1036 Expressions => New_Indexes));
1038 Set_Assignment_OK (Indexed_Comp);
1040 -- Ada 2005 (AI-287): In case of default initialized component, Expr
1041 -- is not present (and therefore we also initialize Expr_Q to empty).
1043 if No (Expr) then
1044 Expr_Q := Empty;
1045 elsif Nkind (Expr) = N_Qualified_Expression then
1046 Expr_Q := Expression (Expr);
1047 else
1048 Expr_Q := Expr;
1049 end if;
1051 if Present (Etype (N)) and then Etype (N) /= Any_Composite then
1052 Comp_Type := Component_Type (Etype (N));
1053 pragma Assert (Comp_Type = Ctype); -- AI-287
1055 elsif Present (Next (First (New_Indexes))) then
1057 -- Ada 2005 (AI-287): Do nothing in case of default initialized
1058 -- component because we have received the component type in
1059 -- the formal parameter Ctype.
1061 -- ??? Some assert pragmas have been added to check if this new
1062 -- formal can be used to replace this code in all cases.
1064 if Present (Expr) then
1066 -- This is a multidimensional array. Recover the component type
1067 -- from the outermost aggregate, because subaggregates do not
1068 -- have an assigned type.
1070 declare
1071 P : Node_Id;
1073 begin
1074 P := Parent (Expr);
1075 while Present (P) loop
1076 if Nkind (P) = N_Aggregate
1077 and then Present (Etype (P))
1078 then
1079 Comp_Type := Component_Type (Etype (P));
1080 exit;
1082 else
1083 P := Parent (P);
1084 end if;
1085 end loop;
1087 pragma Assert (Comp_Type = Ctype); -- AI-287
1088 end;
1089 end if;
1090 end if;
1092 -- Ada 2005 (AI-287): We only analyze the expression in case of non-
1093 -- default initialized components (otherwise Expr_Q is not present).
1095 if Present (Expr_Q)
1096 and then Nkind_In (Expr_Q, N_Aggregate, N_Extension_Aggregate)
1097 then
1098 -- At this stage the Expression may not have been analyzed yet
1099 -- because the array aggregate code has not been updated to use
1100 -- the Expansion_Delayed flag and avoid analysis altogether to
1101 -- solve the same problem (see Resolve_Aggr_Expr). So let us do
1102 -- the analysis of non-array aggregates now in order to get the
1103 -- value of Expansion_Delayed flag for the inner aggregate ???
1105 if Present (Comp_Type) and then not Is_Array_Type (Comp_Type) then
1106 Analyze_And_Resolve (Expr_Q, Comp_Type);
1107 end if;
1109 if Is_Delayed_Aggregate (Expr_Q) then
1111 -- This is either a subaggregate of a multidimensional array,
1112 -- or a component of an array type whose component type is
1113 -- also an array. In the latter case, the expression may have
1114 -- component associations that provide different bounds from
1115 -- those of the component type, and sliding must occur. Instead
1116 -- of decomposing the current aggregate assignment, force the
1117 -- re-analysis of the assignment, so that a temporary will be
1118 -- generated in the usual fashion, and sliding will take place.
1120 if Nkind (Parent (N)) = N_Assignment_Statement
1121 and then Is_Array_Type (Comp_Type)
1122 and then Present (Component_Associations (Expr_Q))
1123 and then Must_Slide (Comp_Type, Etype (Expr_Q))
1124 then
1125 Set_Expansion_Delayed (Expr_Q, False);
1126 Set_Analyzed (Expr_Q, False);
1128 else
1129 return
1130 Add_Loop_Actions (
1131 Late_Expansion (Expr_Q, Etype (Expr_Q), Indexed_Comp));
1132 end if;
1133 end if;
1134 end if;
1136 -- Ada 2005 (AI-287): In case of default initialized component, call
1137 -- the initialization subprogram associated with the component type.
1138 -- If the component type is an access type, add an explicit null
1139 -- assignment, because for the back-end there is an initialization
1140 -- present for the whole aggregate, and no default initialization
1141 -- will take place.
1143 -- In addition, if the component type is controlled, we must call
1144 -- its Initialize procedure explicitly, because there is no explicit
1145 -- object creation that will invoke it otherwise.
1147 if No (Expr) then
1148 if Present (Base_Init_Proc (Base_Type (Ctype)))
1149 or else Has_Task (Base_Type (Ctype))
1150 then
1151 Append_List_To (L,
1152 Build_Initialization_Call (Loc,
1153 Id_Ref => Indexed_Comp,
1154 Typ => Ctype,
1155 With_Default_Init => True));
1157 elsif Is_Access_Type (Ctype) then
1158 Append_To (L,
1159 Make_Assignment_Statement (Loc,
1160 Name => Indexed_Comp,
1161 Expression => Make_Null (Loc)));
1162 end if;
1164 if Needs_Finalization (Ctype) then
1165 Append_To (L,
1166 Make_Init_Call
1167 (Obj_Ref => New_Copy_Tree (Indexed_Comp),
1168 Typ => Ctype));
1169 end if;
1171 else
1172 A :=
1173 Make_OK_Assignment_Statement (Loc,
1174 Name => Indexed_Comp,
1175 Expression => New_Copy_Tree (Expr));
1177 -- The target of the assignment may not have been initialized,
1178 -- so it is not possible to call Finalize as expected in normal
1179 -- controlled assignments. We must also avoid using the primitive
1180 -- _assign (which depends on a valid target, and may for example
1181 -- perform discriminant checks on it).
1183 -- Both Finalize and usage of _assign are disabled by setting
1184 -- No_Ctrl_Actions on the assignment. The rest of the controlled
1185 -- actions are done manually with the proper finalization list
1186 -- coming from the context.
1188 Set_No_Ctrl_Actions (A);
1190 -- If this is an aggregate for an array of arrays, each
1191 -- sub-aggregate will be expanded as well, and even with
1192 -- No_Ctrl_Actions the assignments of inner components will
1193 -- require attachment in their assignments to temporaries. These
1194 -- temporaries must be finalized for each subaggregate, to prevent
1195 -- multiple attachments of the same temporary location to same
1196 -- finalization chain (and consequently circular lists). To ensure
1197 -- that finalization takes place for each subaggregate we wrap the
1198 -- assignment in a block.
1200 if Present (Comp_Type)
1201 and then Needs_Finalization (Comp_Type)
1202 and then Is_Array_Type (Comp_Type)
1203 and then Present (Expr)
1204 then
1205 A :=
1206 Make_Block_Statement (Loc,
1207 Handled_Statement_Sequence =>
1208 Make_Handled_Sequence_Of_Statements (Loc,
1209 Statements => New_List (A)));
1210 end if;
1212 Append_To (L, A);
1214 -- Adjust the tag if tagged (because of possible view
1215 -- conversions), unless compiling for a VM where tags
1216 -- are implicit.
1218 if Present (Comp_Type)
1219 and then Is_Tagged_Type (Comp_Type)
1220 and then Tagged_Type_Expansion
1221 then
1222 declare
1223 Full_Typ : constant Entity_Id := Underlying_Type (Comp_Type);
1225 begin
1226 A :=
1227 Make_OK_Assignment_Statement (Loc,
1228 Name =>
1229 Make_Selected_Component (Loc,
1230 Prefix => New_Copy_Tree (Indexed_Comp),
1231 Selector_Name =>
1232 New_Occurrence_Of
1233 (First_Tag_Component (Full_Typ), Loc)),
1235 Expression =>
1236 Unchecked_Convert_To (RTE (RE_Tag),
1237 New_Occurrence_Of
1238 (Node (First_Elmt (Access_Disp_Table (Full_Typ))),
1239 Loc)));
1241 Append_To (L, A);
1242 end;
1243 end if;
1245 -- Adjust and attach the component to the proper final list, which
1246 -- can be the controller of the outer record object or the final
1247 -- list associated with the scope.
1249 -- If the component is itself an array of controlled types, whose
1250 -- value is given by a sub-aggregate, then the attach calls have
1251 -- been generated when individual subcomponent are assigned, and
1252 -- must not be done again to prevent malformed finalization chains
1253 -- (see comments above, concerning the creation of a block to hold
1254 -- inner finalization actions).
1256 if Present (Comp_Type)
1257 and then Needs_Finalization (Comp_Type)
1258 and then not Is_Limited_Type (Comp_Type)
1259 and then not
1260 (Is_Array_Type (Comp_Type)
1261 and then Is_Controlled (Component_Type (Comp_Type))
1262 and then Nkind (Expr) = N_Aggregate)
1263 then
1264 Append_To (L,
1265 Make_Adjust_Call
1266 (Obj_Ref => New_Copy_Tree (Indexed_Comp),
1267 Typ => Comp_Type));
1268 end if;
1269 end if;
1271 return Add_Loop_Actions (L);
1272 end Gen_Assign;
1274 --------------
1275 -- Gen_Loop --
1276 --------------
1278 function Gen_Loop (L, H : Node_Id; Expr : Node_Id) return List_Id is
1279 L_J : Node_Id;
1281 L_L : Node_Id;
1282 -- Index_Base'(L)
1284 L_H : Node_Id;
1285 -- Index_Base'(H)
1287 L_Range : Node_Id;
1288 -- Index_Base'(L) .. Index_Base'(H)
1290 L_Iteration_Scheme : Node_Id;
1291 -- L_J in Index_Base'(L) .. Index_Base'(H)
1293 L_Body : List_Id;
1294 -- The statements to execute in the loop
1296 S : constant List_Id := New_List;
1297 -- List of statements
1299 Tcopy : Node_Id;
1300 -- Copy of expression tree, used for checking purposes
1302 begin
1303 -- If loop bounds define an empty range return the null statement
1305 if Empty_Range (L, H) then
1306 Append_To (S, Make_Null_Statement (Loc));
1308 -- Ada 2005 (AI-287): Nothing else need to be done in case of
1309 -- default initialized component.
1311 if No (Expr) then
1312 null;
1314 else
1315 -- The expression must be type-checked even though no component
1316 -- of the aggregate will have this value. This is done only for
1317 -- actual components of the array, not for subaggregates. Do
1318 -- the check on a copy, because the expression may be shared
1319 -- among several choices, some of which might be non-null.
1321 if Present (Etype (N))
1322 and then Is_Array_Type (Etype (N))
1323 and then No (Next_Index (Index))
1324 then
1325 Expander_Mode_Save_And_Set (False);
1326 Tcopy := New_Copy_Tree (Expr);
1327 Set_Parent (Tcopy, N);
1328 Analyze_And_Resolve (Tcopy, Component_Type (Etype (N)));
1329 Expander_Mode_Restore;
1330 end if;
1331 end if;
1333 return S;
1335 -- If loop bounds are the same then generate an assignment
1337 elsif Equal (L, H) then
1338 return Gen_Assign (New_Copy_Tree (L), Expr);
1340 -- If H - L <= 2 then generate a sequence of assignments when we are
1341 -- processing the bottom most aggregate and it contains scalar
1342 -- components.
1344 elsif No (Next_Index (Index))
1345 and then Scalar_Comp
1346 and then Local_Compile_Time_Known_Value (L)
1347 and then Local_Compile_Time_Known_Value (H)
1348 and then Local_Expr_Value (H) - Local_Expr_Value (L) <= 2
1349 then
1351 Append_List_To (S, Gen_Assign (New_Copy_Tree (L), Expr));
1352 Append_List_To (S, Gen_Assign (Add (1, To => L), Expr));
1354 if Local_Expr_Value (H) - Local_Expr_Value (L) = 2 then
1355 Append_List_To (S, Gen_Assign (Add (2, To => L), Expr));
1356 end if;
1358 return S;
1359 end if;
1361 -- Otherwise construct the loop, starting with the loop index L_J
1363 L_J := Make_Temporary (Loc, 'J', L);
1365 -- Construct "L .. H" in Index_Base. We use a qualified expression
1366 -- for the bound to convert to the index base, but we don't need
1367 -- to do that if we already have the base type at hand.
1369 if Etype (L) = Index_Base then
1370 L_L := L;
1371 else
1372 L_L :=
1373 Make_Qualified_Expression (Loc,
1374 Subtype_Mark => Index_Base_Name,
1375 Expression => L);
1376 end if;
1378 if Etype (H) = Index_Base then
1379 L_H := H;
1380 else
1381 L_H :=
1382 Make_Qualified_Expression (Loc,
1383 Subtype_Mark => Index_Base_Name,
1384 Expression => H);
1385 end if;
1387 L_Range :=
1388 Make_Range (Loc,
1389 Low_Bound => L_L,
1390 High_Bound => L_H);
1392 -- Construct "for L_J in Index_Base range L .. H"
1394 L_Iteration_Scheme :=
1395 Make_Iteration_Scheme
1396 (Loc,
1397 Loop_Parameter_Specification =>
1398 Make_Loop_Parameter_Specification
1399 (Loc,
1400 Defining_Identifier => L_J,
1401 Discrete_Subtype_Definition => L_Range));
1403 -- Construct the statements to execute in the loop body
1405 L_Body := Gen_Assign (New_Occurrence_Of (L_J, Loc), Expr);
1407 -- Construct the final loop
1409 Append_To (S,
1410 Make_Implicit_Loop_Statement
1411 (Node => N,
1412 Identifier => Empty,
1413 Iteration_Scheme => L_Iteration_Scheme,
1414 Statements => L_Body));
1416 -- A small optimization: if the aggregate is initialized with a box
1417 -- and the component type has no initialization procedure, remove the
1418 -- useless empty loop.
1420 if Nkind (First (S)) = N_Loop_Statement
1421 and then Is_Empty_List (Statements (First (S)))
1422 then
1423 return New_List (Make_Null_Statement (Loc));
1424 else
1425 return S;
1426 end if;
1427 end Gen_Loop;
1429 ---------------
1430 -- Gen_While --
1431 ---------------
1433 -- The code built is
1435 -- W_J : Index_Base := L;
1436 -- while W_J < H loop
1437 -- W_J := Index_Base'Succ (W);
1438 -- L_Body;
1439 -- end loop;
1441 function Gen_While (L, H : Node_Id; Expr : Node_Id) return List_Id is
1442 W_J : Node_Id;
1444 W_Decl : Node_Id;
1445 -- W_J : Base_Type := L;
1447 W_Iteration_Scheme : Node_Id;
1448 -- while W_J < H
1450 W_Index_Succ : Node_Id;
1451 -- Index_Base'Succ (J)
1453 W_Increment : Node_Id;
1454 -- W_J := Index_Base'Succ (W)
1456 W_Body : constant List_Id := New_List;
1457 -- The statements to execute in the loop
1459 S : constant List_Id := New_List;
1460 -- list of statement
1462 begin
1463 -- If loop bounds define an empty range or are equal return null
1465 if Empty_Range (L, H) or else Equal (L, H) then
1466 Append_To (S, Make_Null_Statement (Loc));
1467 return S;
1468 end if;
1470 -- Build the decl of W_J
1472 W_J := Make_Temporary (Loc, 'J', L);
1473 W_Decl :=
1474 Make_Object_Declaration
1475 (Loc,
1476 Defining_Identifier => W_J,
1477 Object_Definition => Index_Base_Name,
1478 Expression => L);
1480 -- Theoretically we should do a New_Copy_Tree (L) here, but we know
1481 -- that in this particular case L is a fresh Expr generated by
1482 -- Add which we are the only ones to use.
1484 Append_To (S, W_Decl);
1486 -- Construct " while W_J < H"
1488 W_Iteration_Scheme :=
1489 Make_Iteration_Scheme
1490 (Loc,
1491 Condition => Make_Op_Lt
1492 (Loc,
1493 Left_Opnd => New_Occurrence_Of (W_J, Loc),
1494 Right_Opnd => New_Copy_Tree (H)));
1496 -- Construct the statements to execute in the loop body
1498 W_Index_Succ :=
1499 Make_Attribute_Reference
1500 (Loc,
1501 Prefix => Index_Base_Name,
1502 Attribute_Name => Name_Succ,
1503 Expressions => New_List (New_Occurrence_Of (W_J, Loc)));
1505 W_Increment :=
1506 Make_OK_Assignment_Statement
1507 (Loc,
1508 Name => New_Occurrence_Of (W_J, Loc),
1509 Expression => W_Index_Succ);
1511 Append_To (W_Body, W_Increment);
1512 Append_List_To (W_Body,
1513 Gen_Assign (New_Occurrence_Of (W_J, Loc), Expr));
1515 -- Construct the final loop
1517 Append_To (S,
1518 Make_Implicit_Loop_Statement
1519 (Node => N,
1520 Identifier => Empty,
1521 Iteration_Scheme => W_Iteration_Scheme,
1522 Statements => W_Body));
1524 return S;
1525 end Gen_While;
1527 ---------------------
1528 -- Index_Base_Name --
1529 ---------------------
1531 function Index_Base_Name return Node_Id is
1532 begin
1533 return New_Occurrence_Of (Index_Base, Sloc (N));
1534 end Index_Base_Name;
1536 ------------------------------------
1537 -- Local_Compile_Time_Known_Value --
1538 ------------------------------------
1540 function Local_Compile_Time_Known_Value (E : Node_Id) return Boolean is
1541 begin
1542 return Compile_Time_Known_Value (E)
1543 or else
1544 (Nkind (E) = N_Attribute_Reference
1545 and then Attribute_Name (E) = Name_Val
1546 and then Compile_Time_Known_Value (First (Expressions (E))));
1547 end Local_Compile_Time_Known_Value;
1549 ----------------------
1550 -- Local_Expr_Value --
1551 ----------------------
1553 function Local_Expr_Value (E : Node_Id) return Uint is
1554 begin
1555 if Compile_Time_Known_Value (E) then
1556 return Expr_Value (E);
1557 else
1558 return Expr_Value (First (Expressions (E)));
1559 end if;
1560 end Local_Expr_Value;
1562 -- Build_Array_Aggr_Code Variables
1564 Assoc : Node_Id;
1565 Choice : Node_Id;
1566 Expr : Node_Id;
1567 Typ : Entity_Id;
1569 Others_Expr : Node_Id := Empty;
1570 Others_Box_Present : Boolean := False;
1572 Aggr_L : constant Node_Id := Low_Bound (Aggregate_Bounds (N));
1573 Aggr_H : constant Node_Id := High_Bound (Aggregate_Bounds (N));
1574 -- The aggregate bounds of this specific sub-aggregate. Note that if
1575 -- the code generated by Build_Array_Aggr_Code is executed then these
1576 -- bounds are OK. Otherwise a Constraint_Error would have been raised.
1578 Aggr_Low : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_L);
1579 Aggr_High : constant Node_Id := Duplicate_Subexpr_No_Checks (Aggr_H);
1580 -- After Duplicate_Subexpr these are side-effect free
1582 Low : Node_Id;
1583 High : Node_Id;
1585 Nb_Choices : Nat := 0;
1586 Table : Case_Table_Type (1 .. Number_Of_Choices (N));
1587 -- Used to sort all the different choice values
1589 Nb_Elements : Int;
1590 -- Number of elements in the positional aggregate
1592 New_Code : constant List_Id := New_List;
1594 -- Start of processing for Build_Array_Aggr_Code
1596 begin
1597 -- First before we start, a special case. if we have a bit packed
1598 -- array represented as a modular type, then clear the value to
1599 -- zero first, to ensure that unused bits are properly cleared.
1601 Typ := Etype (N);
1603 if Present (Typ)
1604 and then Is_Bit_Packed_Array (Typ)
1605 and then Is_Modular_Integer_Type (Packed_Array_Impl_Type (Typ))
1606 then
1607 Append_To (New_Code,
1608 Make_Assignment_Statement (Loc,
1609 Name => New_Copy_Tree (Into),
1610 Expression =>
1611 Unchecked_Convert_To (Typ,
1612 Make_Integer_Literal (Loc, Uint_0))));
1613 end if;
1615 -- If the component type contains tasks, we need to build a Master
1616 -- entity in the current scope, because it will be needed if build-
1617 -- in-place functions are called in the expanded code.
1619 if Nkind (Parent (N)) = N_Object_Declaration and then Has_Task (Typ) then
1620 Build_Master_Entity (Defining_Identifier (Parent (N)));
1621 end if;
1623 -- STEP 1: Process component associations
1625 -- For those associations that may generate a loop, initialize
1626 -- Loop_Actions to collect inserted actions that may be crated.
1628 -- Skip this if no component associations
1630 if No (Expressions (N)) then
1632 -- STEP 1 (a): Sort the discrete choices
1634 Assoc := First (Component_Associations (N));
1635 while Present (Assoc) loop
1636 Choice := First (Choices (Assoc));
1637 while Present (Choice) loop
1638 if Nkind (Choice) = N_Others_Choice then
1639 Set_Loop_Actions (Assoc, New_List);
1641 if Box_Present (Assoc) then
1642 Others_Box_Present := True;
1643 else
1644 Others_Expr := Expression (Assoc);
1645 end if;
1646 exit;
1647 end if;
1649 Get_Index_Bounds (Choice, Low, High);
1651 if Low /= High then
1652 Set_Loop_Actions (Assoc, New_List);
1653 end if;
1655 Nb_Choices := Nb_Choices + 1;
1656 if Box_Present (Assoc) then
1657 Table (Nb_Choices) := (Choice_Lo => Low,
1658 Choice_Hi => High,
1659 Choice_Node => Empty);
1660 else
1661 Table (Nb_Choices) := (Choice_Lo => Low,
1662 Choice_Hi => High,
1663 Choice_Node => Expression (Assoc));
1664 end if;
1665 Next (Choice);
1666 end loop;
1668 Next (Assoc);
1669 end loop;
1671 -- If there is more than one set of choices these must be static
1672 -- and we can therefore sort them. Remember that Nb_Choices does not
1673 -- account for an others choice.
1675 if Nb_Choices > 1 then
1676 Sort_Case_Table (Table);
1677 end if;
1679 -- STEP 1 (b): take care of the whole set of discrete choices
1681 for J in 1 .. Nb_Choices loop
1682 Low := Table (J).Choice_Lo;
1683 High := Table (J).Choice_Hi;
1684 Expr := Table (J).Choice_Node;
1685 Append_List (Gen_Loop (Low, High, Expr), To => New_Code);
1686 end loop;
1688 -- STEP 1 (c): generate the remaining loops to cover others choice
1689 -- We don't need to generate loops over empty gaps, but if there is
1690 -- a single empty range we must analyze the expression for semantics
1692 if Present (Others_Expr) or else Others_Box_Present then
1693 declare
1694 First : Boolean := True;
1696 begin
1697 for J in 0 .. Nb_Choices loop
1698 if J = 0 then
1699 Low := Aggr_Low;
1700 else
1701 Low := Add (1, To => Table (J).Choice_Hi);
1702 end if;
1704 if J = Nb_Choices then
1705 High := Aggr_High;
1706 else
1707 High := Add (-1, To => Table (J + 1).Choice_Lo);
1708 end if;
1710 -- If this is an expansion within an init proc, make
1711 -- sure that discriminant references are replaced by
1712 -- the corresponding discriminal.
1714 if Inside_Init_Proc then
1715 if Is_Entity_Name (Low)
1716 and then Ekind (Entity (Low)) = E_Discriminant
1717 then
1718 Set_Entity (Low, Discriminal (Entity (Low)));
1719 end if;
1721 if Is_Entity_Name (High)
1722 and then Ekind (Entity (High)) = E_Discriminant
1723 then
1724 Set_Entity (High, Discriminal (Entity (High)));
1725 end if;
1726 end if;
1728 if First
1729 or else not Empty_Range (Low, High)
1730 then
1731 First := False;
1732 Append_List
1733 (Gen_Loop (Low, High, Others_Expr), To => New_Code);
1734 end if;
1735 end loop;
1736 end;
1737 end if;
1739 -- STEP 2: Process positional components
1741 else
1742 -- STEP 2 (a): Generate the assignments for each positional element
1743 -- Note that here we have to use Aggr_L rather than Aggr_Low because
1744 -- Aggr_L is analyzed and Add wants an analyzed expression.
1746 Expr := First (Expressions (N));
1747 Nb_Elements := -1;
1748 while Present (Expr) loop
1749 Nb_Elements := Nb_Elements + 1;
1750 Append_List (Gen_Assign (Add (Nb_Elements, To => Aggr_L), Expr),
1751 To => New_Code);
1752 Next (Expr);
1753 end loop;
1755 -- STEP 2 (b): Generate final loop if an others choice is present
1756 -- Here Nb_Elements gives the offset of the last positional element.
1758 if Present (Component_Associations (N)) then
1759 Assoc := Last (Component_Associations (N));
1761 -- Ada 2005 (AI-287)
1763 if Box_Present (Assoc) then
1764 Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L),
1765 Aggr_High,
1766 Empty),
1767 To => New_Code);
1768 else
1769 Expr := Expression (Assoc);
1771 Append_List (Gen_While (Add (Nb_Elements, To => Aggr_L),
1772 Aggr_High,
1773 Expr), -- AI-287
1774 To => New_Code);
1775 end if;
1776 end if;
1777 end if;
1779 return New_Code;
1780 end Build_Array_Aggr_Code;
1782 ----------------------------
1783 -- Build_Record_Aggr_Code --
1784 ----------------------------
1786 function Build_Record_Aggr_Code
1787 (N : Node_Id;
1788 Typ : Entity_Id;
1789 Lhs : Node_Id) return List_Id
1791 Loc : constant Source_Ptr := Sloc (N);
1792 L : constant List_Id := New_List;
1793 N_Typ : constant Entity_Id := Etype (N);
1795 Comp : Node_Id;
1796 Instr : Node_Id;
1797 Ref : Node_Id;
1798 Target : Entity_Id;
1799 Comp_Type : Entity_Id;
1800 Selector : Entity_Id;
1801 Comp_Expr : Node_Id;
1802 Expr_Q : Node_Id;
1804 -- If this is an internal aggregate, the External_Final_List is an
1805 -- expression for the controller record of the enclosing type.
1807 -- If the current aggregate has several controlled components, this
1808 -- expression will appear in several calls to attach to the finali-
1809 -- zation list, and it must not be shared.
1811 Ancestor_Is_Expression : Boolean := False;
1812 Ancestor_Is_Subtype_Mark : Boolean := False;
1814 Init_Typ : Entity_Id := Empty;
1816 Finalization_Done : Boolean := False;
1817 -- True if Generate_Finalization_Actions has already been called; calls
1818 -- after the first do nothing.
1820 function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id;
1821 -- Returns the value that the given discriminant of an ancestor type
1822 -- should receive (in the absence of a conflict with the value provided
1823 -- by an ancestor part of an extension aggregate).
1825 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id);
1826 -- Check that each of the discriminant values defined by the ancestor
1827 -- part of an extension aggregate match the corresponding values
1828 -- provided by either an association of the aggregate or by the
1829 -- constraint imposed by a parent type (RM95-4.3.2(8)).
1831 function Compatible_Int_Bounds
1832 (Agg_Bounds : Node_Id;
1833 Typ_Bounds : Node_Id) return Boolean;
1834 -- Return true if Agg_Bounds are equal or within Typ_Bounds. It is
1835 -- assumed that both bounds are integer ranges.
1837 procedure Generate_Finalization_Actions;
1838 -- Deal with the various controlled type data structure initializations
1839 -- (but only if it hasn't been done already).
1841 function Get_Constraint_Association (T : Entity_Id) return Node_Id;
1842 -- Returns the first discriminant association in the constraint
1843 -- associated with T, if any, otherwise returns Empty.
1845 procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id);
1846 -- If Typ is derived, and constrains discriminants of the parent type,
1847 -- these discriminants are not components of the aggregate, and must be
1848 -- initialized. The assignments are appended to List. The same is done
1849 -- if Typ derives fron an already constrained subtype of a discriminated
1850 -- parent type.
1852 function Get_Explicit_Discriminant_Value (D : Entity_Id) return Node_Id;
1853 -- If the ancestor part is an unconstrained type and further ancestors
1854 -- do not provide discriminants for it, check aggregate components for
1855 -- values of the discriminants.
1857 function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean;
1858 -- Check whether Bounds is a range node and its lower and higher bounds
1859 -- are integers literals.
1861 ---------------------------------
1862 -- Ancestor_Discriminant_Value --
1863 ---------------------------------
1865 function Ancestor_Discriminant_Value (Disc : Entity_Id) return Node_Id is
1866 Assoc : Node_Id;
1867 Assoc_Elmt : Elmt_Id;
1868 Aggr_Comp : Entity_Id;
1869 Corresp_Disc : Entity_Id;
1870 Current_Typ : Entity_Id := Base_Type (Typ);
1871 Parent_Typ : Entity_Id;
1872 Parent_Disc : Entity_Id;
1873 Save_Assoc : Node_Id := Empty;
1875 begin
1876 -- First check any discriminant associations to see if any of them
1877 -- provide a value for the discriminant.
1879 if Present (Discriminant_Specifications (Parent (Current_Typ))) then
1880 Assoc := First (Component_Associations (N));
1881 while Present (Assoc) loop
1882 Aggr_Comp := Entity (First (Choices (Assoc)));
1884 if Ekind (Aggr_Comp) = E_Discriminant then
1885 Save_Assoc := Expression (Assoc);
1887 Corresp_Disc := Corresponding_Discriminant (Aggr_Comp);
1888 while Present (Corresp_Disc) loop
1890 -- If found a corresponding discriminant then return the
1891 -- value given in the aggregate. (Note: this is not
1892 -- correct in the presence of side effects. ???)
1894 if Disc = Corresp_Disc then
1895 return Duplicate_Subexpr (Expression (Assoc));
1896 end if;
1898 Corresp_Disc :=
1899 Corresponding_Discriminant (Corresp_Disc);
1900 end loop;
1901 end if;
1903 Next (Assoc);
1904 end loop;
1905 end if;
1907 -- No match found in aggregate, so chain up parent types to find
1908 -- a constraint that defines the value of the discriminant.
1910 Parent_Typ := Etype (Current_Typ);
1911 while Current_Typ /= Parent_Typ loop
1912 if Has_Discriminants (Parent_Typ)
1913 and then not Has_Unknown_Discriminants (Parent_Typ)
1914 then
1915 Parent_Disc := First_Discriminant (Parent_Typ);
1917 -- We either get the association from the subtype indication
1918 -- of the type definition itself, or from the discriminant
1919 -- constraint associated with the type entity (which is
1920 -- preferable, but it's not always present ???)
1922 if Is_Empty_Elmt_List (
1923 Discriminant_Constraint (Current_Typ))
1924 then
1925 Assoc := Get_Constraint_Association (Current_Typ);
1926 Assoc_Elmt := No_Elmt;
1927 else
1928 Assoc_Elmt :=
1929 First_Elmt (Discriminant_Constraint (Current_Typ));
1930 Assoc := Node (Assoc_Elmt);
1931 end if;
1933 -- Traverse the discriminants of the parent type looking
1934 -- for one that corresponds.
1936 while Present (Parent_Disc) and then Present (Assoc) loop
1937 Corresp_Disc := Parent_Disc;
1938 while Present (Corresp_Disc)
1939 and then Disc /= Corresp_Disc
1940 loop
1941 Corresp_Disc :=
1942 Corresponding_Discriminant (Corresp_Disc);
1943 end loop;
1945 if Disc = Corresp_Disc then
1946 if Nkind (Assoc) = N_Discriminant_Association then
1947 Assoc := Expression (Assoc);
1948 end if;
1950 -- If the located association directly denotes
1951 -- a discriminant, then use the value of a saved
1952 -- association of the aggregate. This is an approach
1953 -- used to handle certain cases involving multiple
1954 -- discriminants mapped to a single discriminant of
1955 -- a descendant. It's not clear how to locate the
1956 -- appropriate discriminant value for such cases. ???
1958 if Is_Entity_Name (Assoc)
1959 and then Ekind (Entity (Assoc)) = E_Discriminant
1960 then
1961 Assoc := Save_Assoc;
1962 end if;
1964 return Duplicate_Subexpr (Assoc);
1965 end if;
1967 Next_Discriminant (Parent_Disc);
1969 if No (Assoc_Elmt) then
1970 Next (Assoc);
1971 else
1972 Next_Elmt (Assoc_Elmt);
1973 if Present (Assoc_Elmt) then
1974 Assoc := Node (Assoc_Elmt);
1975 else
1976 Assoc := Empty;
1977 end if;
1978 end if;
1979 end loop;
1980 end if;
1982 Current_Typ := Parent_Typ;
1983 Parent_Typ := Etype (Current_Typ);
1984 end loop;
1986 -- In some cases there's no ancestor value to locate (such as
1987 -- when an ancestor part given by an expression defines the
1988 -- discriminant value).
1990 return Empty;
1991 end Ancestor_Discriminant_Value;
1993 ----------------------------------
1994 -- Check_Ancestor_Discriminants --
1995 ----------------------------------
1997 procedure Check_Ancestor_Discriminants (Anc_Typ : Entity_Id) is
1998 Discr : Entity_Id;
1999 Disc_Value : Node_Id;
2000 Cond : Node_Id;
2002 begin
2003 Discr := First_Discriminant (Base_Type (Anc_Typ));
2004 while Present (Discr) loop
2005 Disc_Value := Ancestor_Discriminant_Value (Discr);
2007 if Present (Disc_Value) then
2008 Cond := Make_Op_Ne (Loc,
2009 Left_Opnd =>
2010 Make_Selected_Component (Loc,
2011 Prefix => New_Copy_Tree (Target),
2012 Selector_Name => New_Occurrence_Of (Discr, Loc)),
2013 Right_Opnd => Disc_Value);
2015 Append_To (L,
2016 Make_Raise_Constraint_Error (Loc,
2017 Condition => Cond,
2018 Reason => CE_Discriminant_Check_Failed));
2019 end if;
2021 Next_Discriminant (Discr);
2022 end loop;
2023 end Check_Ancestor_Discriminants;
2025 ---------------------------
2026 -- Compatible_Int_Bounds --
2027 ---------------------------
2029 function Compatible_Int_Bounds
2030 (Agg_Bounds : Node_Id;
2031 Typ_Bounds : Node_Id) return Boolean
2033 Agg_Lo : constant Uint := Intval (Low_Bound (Agg_Bounds));
2034 Agg_Hi : constant Uint := Intval (High_Bound (Agg_Bounds));
2035 Typ_Lo : constant Uint := Intval (Low_Bound (Typ_Bounds));
2036 Typ_Hi : constant Uint := Intval (High_Bound (Typ_Bounds));
2037 begin
2038 return Typ_Lo <= Agg_Lo and then Agg_Hi <= Typ_Hi;
2039 end Compatible_Int_Bounds;
2041 --------------------------------
2042 -- Get_Constraint_Association --
2043 --------------------------------
2045 function Get_Constraint_Association (T : Entity_Id) return Node_Id is
2046 Indic : Node_Id;
2047 Typ : Entity_Id;
2049 begin
2050 Typ := T;
2052 -- Handle private types in instances
2054 if In_Instance
2055 and then Is_Private_Type (Typ)
2056 and then Present (Full_View (Typ))
2057 then
2058 Typ := Full_View (Typ);
2059 end if;
2061 Indic := Subtype_Indication (Type_Definition (Parent (Typ)));
2063 -- ??? Also need to cover case of a type mark denoting a subtype
2064 -- with constraint.
2066 if Nkind (Indic) = N_Subtype_Indication
2067 and then Present (Constraint (Indic))
2068 then
2069 return First (Constraints (Constraint (Indic)));
2070 end if;
2072 return Empty;
2073 end Get_Constraint_Association;
2075 -------------------------------------
2076 -- Get_Explicit_Discriminant_Value --
2077 -------------------------------------
2079 function Get_Explicit_Discriminant_Value
2080 (D : Entity_Id) return Node_Id
2082 Assoc : Node_Id;
2083 Choice : Node_Id;
2084 Val : Node_Id;
2086 begin
2087 -- The aggregate has been normalized and all associations have a
2088 -- single choice.
2090 Assoc := First (Component_Associations (N));
2091 while Present (Assoc) loop
2092 Choice := First (Choices (Assoc));
2094 if Chars (Choice) = Chars (D) then
2095 Val := Expression (Assoc);
2096 Remove (Assoc);
2097 return Val;
2098 end if;
2100 Next (Assoc);
2101 end loop;
2103 return Empty;
2104 end Get_Explicit_Discriminant_Value;
2106 -------------------------------
2107 -- Init_Hidden_Discriminants --
2108 -------------------------------
2110 procedure Init_Hidden_Discriminants (Typ : Entity_Id; List : List_Id) is
2111 Btype : Entity_Id;
2112 Parent_Type : Entity_Id;
2113 Disc : Entity_Id;
2114 Discr_Val : Elmt_Id;
2116 begin
2117 -- The constraints on the hidden discriminants, if present, are kept
2118 -- in the Stored_Constraint list of the type itself, or in that of
2119 -- the base type.
2121 Btype := Base_Type (Typ);
2122 while Is_Derived_Type (Btype)
2123 and then (Present (Stored_Constraint (Btype))
2124 or else
2125 Present (Stored_Constraint (Typ)))
2126 loop
2127 Parent_Type := Etype (Btype);
2129 if not Has_Discriminants (Parent_Type) then
2130 return;
2131 end if;
2133 Disc := First_Discriminant (Parent_Type);
2135 -- We know that one of the stored-constraint lists is present
2137 if Present (Stored_Constraint (Btype)) then
2138 Discr_Val := First_Elmt (Stored_Constraint (Btype));
2140 -- For private extension, stored constraint may be on full view
2142 elsif Is_Private_Type (Btype)
2143 and then Present (Full_View (Btype))
2144 and then Present (Stored_Constraint (Full_View (Btype)))
2145 then
2146 Discr_Val := First_Elmt (Stored_Constraint (Full_View (Btype)));
2148 else
2149 Discr_Val := First_Elmt (Stored_Constraint (Typ));
2150 end if;
2152 while Present (Discr_Val) loop
2154 -- Only those discriminants of the parent that are not
2155 -- renamed by discriminants of the derived type need to
2156 -- be added explicitly.
2158 if not Is_Entity_Name (Node (Discr_Val))
2159 or else Ekind (Entity (Node (Discr_Val))) /= E_Discriminant
2160 then
2161 Comp_Expr :=
2162 Make_Selected_Component (Loc,
2163 Prefix => New_Copy_Tree (Target),
2164 Selector_Name => New_Occurrence_Of (Disc, Loc));
2166 Instr :=
2167 Make_OK_Assignment_Statement (Loc,
2168 Name => Comp_Expr,
2169 Expression => New_Copy_Tree (Node (Discr_Val)));
2171 Set_No_Ctrl_Actions (Instr);
2172 Append_To (List, Instr);
2173 end if;
2175 Next_Discriminant (Disc);
2176 Next_Elmt (Discr_Val);
2177 end loop;
2179 Btype := Base_Type (Parent_Type);
2180 end loop;
2181 end Init_Hidden_Discriminants;
2183 -------------------------
2184 -- Is_Int_Range_Bounds --
2185 -------------------------
2187 function Is_Int_Range_Bounds (Bounds : Node_Id) return Boolean is
2188 begin
2189 return Nkind (Bounds) = N_Range
2190 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
2191 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal;
2192 end Is_Int_Range_Bounds;
2194 -----------------------------------
2195 -- Generate_Finalization_Actions --
2196 -----------------------------------
2198 procedure Generate_Finalization_Actions is
2199 begin
2200 -- Do the work only the first time this is called
2202 if Finalization_Done then
2203 return;
2204 end if;
2206 Finalization_Done := True;
2208 -- Determine the external finalization list. It is either the
2209 -- finalization list of the outer-scope or the one coming from an
2210 -- outer aggregate. When the target is not a temporary, the proper
2211 -- scope is the scope of the target rather than the potentially
2212 -- transient current scope.
2214 if Is_Controlled (Typ) and then Ancestor_Is_Subtype_Mark then
2215 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2216 Set_Assignment_OK (Ref);
2218 Append_To (L,
2219 Make_Procedure_Call_Statement (Loc,
2220 Name =>
2221 New_Occurrence_Of
2222 (Find_Prim_Op (Init_Typ, Name_Initialize), Loc),
2223 Parameter_Associations => New_List (New_Copy_Tree (Ref))));
2224 end if;
2225 end Generate_Finalization_Actions;
2227 function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result;
2228 -- If default expression of a component mentions a discriminant of the
2229 -- type, it must be rewritten as the discriminant of the target object.
2231 function Replace_Type (Expr : Node_Id) return Traverse_Result;
2232 -- If the aggregate contains a self-reference, traverse each expression
2233 -- to replace a possible self-reference with a reference to the proper
2234 -- component of the target of the assignment.
2236 --------------------------
2237 -- Rewrite_Discriminant --
2238 --------------------------
2240 function Rewrite_Discriminant (Expr : Node_Id) return Traverse_Result is
2241 begin
2242 if Is_Entity_Name (Expr)
2243 and then Present (Entity (Expr))
2244 and then Ekind (Entity (Expr)) = E_In_Parameter
2245 and then Present (Discriminal_Link (Entity (Expr)))
2246 and then Scope (Discriminal_Link (Entity (Expr))) =
2247 Base_Type (Etype (N))
2248 then
2249 Rewrite (Expr,
2250 Make_Selected_Component (Loc,
2251 Prefix => New_Copy_Tree (Lhs),
2252 Selector_Name => Make_Identifier (Loc, Chars (Expr))));
2253 end if;
2255 return OK;
2256 end Rewrite_Discriminant;
2258 ------------------
2259 -- Replace_Type --
2260 ------------------
2262 function Replace_Type (Expr : Node_Id) return Traverse_Result is
2263 begin
2264 -- Note regarding the Root_Type test below: Aggregate components for
2265 -- self-referential types include attribute references to the current
2266 -- instance, of the form: Typ'access, etc.. These references are
2267 -- rewritten as references to the target of the aggregate: the
2268 -- left-hand side of an assignment, the entity in a declaration,
2269 -- or a temporary. Without this test, we would improperly extended
2270 -- this rewriting to attribute references whose prefix was not the
2271 -- type of the aggregate.
2273 if Nkind (Expr) = N_Attribute_Reference
2274 and then Is_Entity_Name (Prefix (Expr))
2275 and then Is_Type (Entity (Prefix (Expr)))
2276 and then Root_Type (Etype (N)) = Root_Type (Entity (Prefix (Expr)))
2277 then
2278 if Is_Entity_Name (Lhs) then
2279 Rewrite (Prefix (Expr),
2280 New_Occurrence_Of (Entity (Lhs), Loc));
2282 elsif Nkind (Lhs) = N_Selected_Component then
2283 Rewrite (Expr,
2284 Make_Attribute_Reference (Loc,
2285 Attribute_Name => Name_Unrestricted_Access,
2286 Prefix => New_Copy_Tree (Lhs)));
2287 Set_Analyzed (Parent (Expr), False);
2289 else
2290 Rewrite (Expr,
2291 Make_Attribute_Reference (Loc,
2292 Attribute_Name => Name_Unrestricted_Access,
2293 Prefix => New_Copy_Tree (Lhs)));
2294 Set_Analyzed (Parent (Expr), False);
2295 end if;
2296 end if;
2298 return OK;
2299 end Replace_Type;
2301 procedure Replace_Self_Reference is
2302 new Traverse_Proc (Replace_Type);
2304 procedure Replace_Discriminants is
2305 new Traverse_Proc (Rewrite_Discriminant);
2307 -- Start of processing for Build_Record_Aggr_Code
2309 begin
2310 if Has_Self_Reference (N) then
2311 Replace_Self_Reference (N);
2312 end if;
2314 -- If the target of the aggregate is class-wide, we must convert it
2315 -- to the actual type of the aggregate, so that the proper components
2316 -- are visible. We know already that the types are compatible.
2318 if Present (Etype (Lhs))
2319 and then Is_Class_Wide_Type (Etype (Lhs))
2320 then
2321 Target := Unchecked_Convert_To (Typ, Lhs);
2322 else
2323 Target := Lhs;
2324 end if;
2326 -- Deal with the ancestor part of extension aggregates or with the
2327 -- discriminants of the root type.
2329 if Nkind (N) = N_Extension_Aggregate then
2330 declare
2331 Ancestor : constant Node_Id := Ancestor_Part (N);
2332 Assign : List_Id;
2334 begin
2335 -- If the ancestor part is a subtype mark "T", we generate
2337 -- init-proc (T (tmp)); if T is constrained and
2338 -- init-proc (S (tmp)); where S applies an appropriate
2339 -- constraint if T is unconstrained
2341 if Is_Entity_Name (Ancestor)
2342 and then Is_Type (Entity (Ancestor))
2343 then
2344 Ancestor_Is_Subtype_Mark := True;
2346 if Is_Constrained (Entity (Ancestor)) then
2347 Init_Typ := Entity (Ancestor);
2349 -- For an ancestor part given by an unconstrained type mark,
2350 -- create a subtype constrained by appropriate corresponding
2351 -- discriminant values coming from either associations of the
2352 -- aggregate or a constraint on a parent type. The subtype will
2353 -- be used to generate the correct default value for the
2354 -- ancestor part.
2356 elsif Has_Discriminants (Entity (Ancestor)) then
2357 declare
2358 Anc_Typ : constant Entity_Id := Entity (Ancestor);
2359 Anc_Constr : constant List_Id := New_List;
2360 Discrim : Entity_Id;
2361 Disc_Value : Node_Id;
2362 New_Indic : Node_Id;
2363 Subt_Decl : Node_Id;
2365 begin
2366 Discrim := First_Discriminant (Anc_Typ);
2367 while Present (Discrim) loop
2368 Disc_Value := Ancestor_Discriminant_Value (Discrim);
2370 -- If no usable discriminant in ancestors, check
2371 -- whether aggregate has an explicit value for it.
2373 if No (Disc_Value) then
2374 Disc_Value :=
2375 Get_Explicit_Discriminant_Value (Discrim);
2376 end if;
2378 Append_To (Anc_Constr, Disc_Value);
2379 Next_Discriminant (Discrim);
2380 end loop;
2382 New_Indic :=
2383 Make_Subtype_Indication (Loc,
2384 Subtype_Mark => New_Occurrence_Of (Anc_Typ, Loc),
2385 Constraint =>
2386 Make_Index_Or_Discriminant_Constraint (Loc,
2387 Constraints => Anc_Constr));
2389 Init_Typ := Create_Itype (Ekind (Anc_Typ), N);
2391 Subt_Decl :=
2392 Make_Subtype_Declaration (Loc,
2393 Defining_Identifier => Init_Typ,
2394 Subtype_Indication => New_Indic);
2396 -- Itypes must be analyzed with checks off Declaration
2397 -- must have a parent for proper handling of subsidiary
2398 -- actions.
2400 Set_Parent (Subt_Decl, N);
2401 Analyze (Subt_Decl, Suppress => All_Checks);
2402 end;
2403 end if;
2405 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2406 Set_Assignment_OK (Ref);
2408 if not Is_Interface (Init_Typ) then
2409 Append_List_To (L,
2410 Build_Initialization_Call (Loc,
2411 Id_Ref => Ref,
2412 Typ => Init_Typ,
2413 In_Init_Proc => Within_Init_Proc,
2414 With_Default_Init => Has_Default_Init_Comps (N)
2415 or else
2416 Has_Task (Base_Type (Init_Typ))));
2418 if Is_Constrained (Entity (Ancestor))
2419 and then Has_Discriminants (Entity (Ancestor))
2420 then
2421 Check_Ancestor_Discriminants (Entity (Ancestor));
2422 end if;
2423 end if;
2425 -- Handle calls to C++ constructors
2427 elsif Is_CPP_Constructor_Call (Ancestor) then
2428 Init_Typ := Etype (Ancestor);
2429 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2430 Set_Assignment_OK (Ref);
2432 Append_List_To (L,
2433 Build_Initialization_Call (Loc,
2434 Id_Ref => Ref,
2435 Typ => Init_Typ,
2436 In_Init_Proc => Within_Init_Proc,
2437 With_Default_Init => Has_Default_Init_Comps (N),
2438 Constructor_Ref => Ancestor));
2440 -- Ada 2005 (AI-287): If the ancestor part is an aggregate of
2441 -- limited type, a recursive call expands the ancestor. Note that
2442 -- in the limited case, the ancestor part must be either a
2443 -- function call (possibly qualified, or wrapped in an unchecked
2444 -- conversion) or aggregate (definitely qualified).
2446 -- The ancestor part can also be a function call (that may be
2447 -- transformed into an explicit dereference) or a qualification
2448 -- of one such.
2450 elsif Is_Limited_Type (Etype (Ancestor))
2451 and then Nkind_In (Unqualify (Ancestor), N_Aggregate,
2452 N_Extension_Aggregate)
2453 then
2454 Ancestor_Is_Expression := True;
2456 -- Set up finalization data for enclosing record, because
2457 -- controlled subcomponents of the ancestor part will be
2458 -- attached to it.
2460 Generate_Finalization_Actions;
2462 Append_List_To (L,
2463 Build_Record_Aggr_Code
2464 (N => Unqualify (Ancestor),
2465 Typ => Etype (Unqualify (Ancestor)),
2466 Lhs => Target));
2468 -- If the ancestor part is an expression "E", we generate
2470 -- T (tmp) := E;
2472 -- In Ada 2005, this includes the case of a (possibly qualified)
2473 -- limited function call. The assignment will turn into a
2474 -- build-in-place function call (for further details, see
2475 -- Make_Build_In_Place_Call_In_Assignment).
2477 else
2478 Ancestor_Is_Expression := True;
2479 Init_Typ := Etype (Ancestor);
2481 -- If the ancestor part is an aggregate, force its full
2482 -- expansion, which was delayed.
2484 if Nkind_In (Unqualify (Ancestor), N_Aggregate,
2485 N_Extension_Aggregate)
2486 then
2487 Set_Analyzed (Ancestor, False);
2488 Set_Analyzed (Expression (Ancestor), False);
2489 end if;
2491 Ref := Convert_To (Init_Typ, New_Copy_Tree (Target));
2492 Set_Assignment_OK (Ref);
2494 -- Make the assignment without usual controlled actions, since
2495 -- we only want to Adjust afterwards, but not to Finalize
2496 -- beforehand. Add manual Adjust when necessary.
2498 Assign := New_List (
2499 Make_OK_Assignment_Statement (Loc,
2500 Name => Ref,
2501 Expression => Ancestor));
2502 Set_No_Ctrl_Actions (First (Assign));
2504 -- Assign the tag now to make sure that the dispatching call in
2505 -- the subsequent deep_adjust works properly (unless VM_Target,
2506 -- where tags are implicit).
2508 if Tagged_Type_Expansion then
2509 Instr :=
2510 Make_OK_Assignment_Statement (Loc,
2511 Name =>
2512 Make_Selected_Component (Loc,
2513 Prefix => New_Copy_Tree (Target),
2514 Selector_Name =>
2515 New_Occurrence_Of
2516 (First_Tag_Component (Base_Type (Typ)), Loc)),
2518 Expression =>
2519 Unchecked_Convert_To (RTE (RE_Tag),
2520 New_Occurrence_Of
2521 (Node (First_Elmt
2522 (Access_Disp_Table (Base_Type (Typ)))),
2523 Loc)));
2525 Set_Assignment_OK (Name (Instr));
2526 Append_To (Assign, Instr);
2528 -- Ada 2005 (AI-251): If tagged type has progenitors we must
2529 -- also initialize tags of the secondary dispatch tables.
2531 if Has_Interfaces (Base_Type (Typ)) then
2532 Init_Secondary_Tags
2533 (Typ => Base_Type (Typ),
2534 Target => Target,
2535 Stmts_List => Assign);
2536 end if;
2537 end if;
2539 -- Call Adjust manually
2541 if Needs_Finalization (Etype (Ancestor))
2542 and then not Is_Limited_Type (Etype (Ancestor))
2543 then
2544 Append_To (Assign,
2545 Make_Adjust_Call
2546 (Obj_Ref => New_Copy_Tree (Ref),
2547 Typ => Etype (Ancestor)));
2548 end if;
2550 Append_To (L,
2551 Make_Unsuppress_Block (Loc, Name_Discriminant_Check, Assign));
2553 if Has_Discriminants (Init_Typ) then
2554 Check_Ancestor_Discriminants (Init_Typ);
2555 end if;
2556 end if;
2557 end;
2559 -- Generate assignments of hidden discriminants. If the base type is
2560 -- an unchecked union, the discriminants are unknown to the back-end
2561 -- and absent from a value of the type, so assignments for them are
2562 -- not emitted.
2564 if Has_Discriminants (Typ)
2565 and then not Is_Unchecked_Union (Base_Type (Typ))
2566 then
2567 Init_Hidden_Discriminants (Typ, L);
2568 end if;
2570 -- Normal case (not an extension aggregate)
2572 else
2573 -- Generate the discriminant expressions, component by component.
2574 -- If the base type is an unchecked union, the discriminants are
2575 -- unknown to the back-end and absent from a value of the type, so
2576 -- assignments for them are not emitted.
2578 if Has_Discriminants (Typ)
2579 and then not Is_Unchecked_Union (Base_Type (Typ))
2580 then
2581 Init_Hidden_Discriminants (Typ, L);
2583 -- Generate discriminant init values for the visible discriminants
2585 declare
2586 Discriminant : Entity_Id;
2587 Discriminant_Value : Node_Id;
2589 begin
2590 Discriminant := First_Stored_Discriminant (Typ);
2591 while Present (Discriminant) loop
2592 Comp_Expr :=
2593 Make_Selected_Component (Loc,
2594 Prefix => New_Copy_Tree (Target),
2595 Selector_Name => New_Occurrence_Of (Discriminant, Loc));
2597 Discriminant_Value :=
2598 Get_Discriminant_Value (
2599 Discriminant,
2600 N_Typ,
2601 Discriminant_Constraint (N_Typ));
2603 Instr :=
2604 Make_OK_Assignment_Statement (Loc,
2605 Name => Comp_Expr,
2606 Expression => New_Copy_Tree (Discriminant_Value));
2608 Set_No_Ctrl_Actions (Instr);
2609 Append_To (L, Instr);
2611 Next_Stored_Discriminant (Discriminant);
2612 end loop;
2613 end;
2614 end if;
2615 end if;
2617 -- For CPP types we generate an implicit call to the C++ default
2618 -- constructor to ensure the proper initialization of the _Tag
2619 -- component.
2621 if Is_CPP_Class (Root_Type (Typ)) and then CPP_Num_Prims (Typ) > 0 then
2622 Invoke_Constructor : declare
2623 CPP_Parent : constant Entity_Id := Enclosing_CPP_Parent (Typ);
2625 procedure Invoke_IC_Proc (T : Entity_Id);
2626 -- Recursive routine used to climb to parents. Required because
2627 -- parents must be initialized before descendants to ensure
2628 -- propagation of inherited C++ slots.
2630 --------------------
2631 -- Invoke_IC_Proc --
2632 --------------------
2634 procedure Invoke_IC_Proc (T : Entity_Id) is
2635 begin
2636 -- Avoid generating extra calls. Initialization required
2637 -- only for types defined from the level of derivation of
2638 -- type of the constructor and the type of the aggregate.
2640 if T = CPP_Parent then
2641 return;
2642 end if;
2644 Invoke_IC_Proc (Etype (T));
2646 -- Generate call to the IC routine
2648 if Present (CPP_Init_Proc (T)) then
2649 Append_To (L,
2650 Make_Procedure_Call_Statement (Loc,
2651 New_Occurrence_Of (CPP_Init_Proc (T), Loc)));
2652 end if;
2653 end Invoke_IC_Proc;
2655 -- Start of processing for Invoke_Constructor
2657 begin
2658 -- Implicit invocation of the C++ constructor
2660 if Nkind (N) = N_Aggregate then
2661 Append_To (L,
2662 Make_Procedure_Call_Statement (Loc,
2663 Name =>
2664 New_Occurrence_Of (Base_Init_Proc (CPP_Parent), Loc),
2665 Parameter_Associations => New_List (
2666 Unchecked_Convert_To (CPP_Parent,
2667 New_Copy_Tree (Lhs)))));
2668 end if;
2670 Invoke_IC_Proc (Typ);
2671 end Invoke_Constructor;
2672 end if;
2674 -- Generate the assignments, component by component
2676 -- tmp.comp1 := Expr1_From_Aggr;
2677 -- tmp.comp2 := Expr2_From_Aggr;
2678 -- ....
2680 Comp := First (Component_Associations (N));
2681 while Present (Comp) loop
2682 Selector := Entity (First (Choices (Comp)));
2684 -- C++ constructors
2686 if Is_CPP_Constructor_Call (Expression (Comp)) then
2687 Append_List_To (L,
2688 Build_Initialization_Call (Loc,
2689 Id_Ref =>
2690 Make_Selected_Component (Loc,
2691 Prefix => New_Copy_Tree (Target),
2692 Selector_Name => New_Occurrence_Of (Selector, Loc)),
2693 Typ => Etype (Selector),
2694 Enclos_Type => Typ,
2695 With_Default_Init => True,
2696 Constructor_Ref => Expression (Comp)));
2698 -- Ada 2005 (AI-287): For each default-initialized component generate
2699 -- a call to the corresponding IP subprogram if available.
2701 elsif Box_Present (Comp)
2702 and then Has_Non_Null_Base_Init_Proc (Etype (Selector))
2703 then
2704 if Ekind (Selector) /= E_Discriminant then
2705 Generate_Finalization_Actions;
2706 end if;
2708 -- Ada 2005 (AI-287): If the component type has tasks then
2709 -- generate the activation chain and master entities (except
2710 -- in case of an allocator because in that case these entities
2711 -- are generated by Build_Task_Allocate_Block_With_Init_Stmts).
2713 declare
2714 Ctype : constant Entity_Id := Etype (Selector);
2715 Inside_Allocator : Boolean := False;
2716 P : Node_Id := Parent (N);
2718 begin
2719 if Is_Task_Type (Ctype) or else Has_Task (Ctype) then
2720 while Present (P) loop
2721 if Nkind (P) = N_Allocator then
2722 Inside_Allocator := True;
2723 exit;
2724 end if;
2726 P := Parent (P);
2727 end loop;
2729 if not Inside_Init_Proc and not Inside_Allocator then
2730 Build_Activation_Chain_Entity (N);
2731 end if;
2732 end if;
2733 end;
2735 Append_List_To (L,
2736 Build_Initialization_Call (Loc,
2737 Id_Ref => Make_Selected_Component (Loc,
2738 Prefix => New_Copy_Tree (Target),
2739 Selector_Name =>
2740 New_Occurrence_Of (Selector, Loc)),
2741 Typ => Etype (Selector),
2742 Enclos_Type => Typ,
2743 With_Default_Init => True));
2745 -- Prepare for component assignment
2747 elsif Ekind (Selector) /= E_Discriminant
2748 or else Nkind (N) = N_Extension_Aggregate
2749 then
2750 -- All the discriminants have now been assigned
2752 -- This is now a good moment to initialize and attach all the
2753 -- controllers. Their position may depend on the discriminants.
2755 if Ekind (Selector) /= E_Discriminant then
2756 Generate_Finalization_Actions;
2757 end if;
2759 Comp_Type := Underlying_Type (Etype (Selector));
2760 Comp_Expr :=
2761 Make_Selected_Component (Loc,
2762 Prefix => New_Copy_Tree (Target),
2763 Selector_Name => New_Occurrence_Of (Selector, Loc));
2765 if Nkind (Expression (Comp)) = N_Qualified_Expression then
2766 Expr_Q := Expression (Expression (Comp));
2767 else
2768 Expr_Q := Expression (Comp);
2769 end if;
2771 -- Now either create the assignment or generate the code for the
2772 -- inner aggregate top-down.
2774 if Is_Delayed_Aggregate (Expr_Q) then
2776 -- We have the following case of aggregate nesting inside
2777 -- an object declaration:
2779 -- type Arr_Typ is array (Integer range <>) of ...;
2781 -- type Rec_Typ (...) is record
2782 -- Obj_Arr_Typ : Arr_Typ (A .. B);
2783 -- end record;
2785 -- Obj_Rec_Typ : Rec_Typ := (...,
2786 -- Obj_Arr_Typ => (X => (...), Y => (...)));
2788 -- The length of the ranges of the aggregate and Obj_Add_Typ
2789 -- are equal (B - A = Y - X), but they do not coincide (X /=
2790 -- A and B /= Y). This case requires array sliding which is
2791 -- performed in the following manner:
2793 -- subtype Arr_Sub is Arr_Typ (X .. Y);
2794 -- Temp : Arr_Sub;
2795 -- Temp (X) := (...);
2796 -- ...
2797 -- Temp (Y) := (...);
2798 -- Obj_Rec_Typ.Obj_Arr_Typ := Temp;
2800 if Ekind (Comp_Type) = E_Array_Subtype
2801 and then Is_Int_Range_Bounds (Aggregate_Bounds (Expr_Q))
2802 and then Is_Int_Range_Bounds (First_Index (Comp_Type))
2803 and then not
2804 Compatible_Int_Bounds
2805 (Agg_Bounds => Aggregate_Bounds (Expr_Q),
2806 Typ_Bounds => First_Index (Comp_Type))
2807 then
2808 -- Create the array subtype with bounds equal to those of
2809 -- the corresponding aggregate.
2811 declare
2812 SubE : constant Entity_Id := Make_Temporary (Loc, 'T');
2814 SubD : constant Node_Id :=
2815 Make_Subtype_Declaration (Loc,
2816 Defining_Identifier => SubE,
2817 Subtype_Indication =>
2818 Make_Subtype_Indication (Loc,
2819 Subtype_Mark =>
2820 New_Occurrence_Of (Etype (Comp_Type), Loc),
2821 Constraint =>
2822 Make_Index_Or_Discriminant_Constraint
2823 (Loc,
2824 Constraints => New_List (
2825 New_Copy_Tree
2826 (Aggregate_Bounds (Expr_Q))))));
2828 -- Create a temporary array of the above subtype which
2829 -- will be used to capture the aggregate assignments.
2831 TmpE : constant Entity_Id := Make_Temporary (Loc, 'A', N);
2833 TmpD : constant Node_Id :=
2834 Make_Object_Declaration (Loc,
2835 Defining_Identifier => TmpE,
2836 Object_Definition => New_Occurrence_Of (SubE, Loc));
2838 begin
2839 Set_No_Initialization (TmpD);
2840 Append_To (L, SubD);
2841 Append_To (L, TmpD);
2843 -- Expand aggregate into assignments to the temp array
2845 Append_List_To (L,
2846 Late_Expansion (Expr_Q, Comp_Type,
2847 New_Occurrence_Of (TmpE, Loc)));
2849 -- Slide
2851 Append_To (L,
2852 Make_Assignment_Statement (Loc,
2853 Name => New_Copy_Tree (Comp_Expr),
2854 Expression => New_Occurrence_Of (TmpE, Loc)));
2855 end;
2857 -- Normal case (sliding not required)
2859 else
2860 Append_List_To (L,
2861 Late_Expansion (Expr_Q, Comp_Type, Comp_Expr));
2862 end if;
2864 -- Expr_Q is not delayed aggregate
2866 else
2867 if Has_Discriminants (Typ) then
2868 Replace_Discriminants (Expr_Q);
2870 -- If the component is an array type that depends on
2871 -- discriminants, and the expression is a single Others
2872 -- clause, create an explicit subtype for it because the
2873 -- backend has troubles recovering the actual bounds.
2875 if Nkind (Expr_Q) = N_Aggregate
2876 and then Is_Array_Type (Comp_Type)
2877 and then Present (Component_Associations (Expr_Q))
2878 then
2879 declare
2880 Assoc : constant Node_Id :=
2881 First (Component_Associations (Expr_Q));
2882 Decl : Node_Id;
2884 begin
2885 if Nkind (First (Choices (Assoc))) = N_Others_Choice
2886 then
2887 Decl :=
2888 Build_Actual_Subtype_Of_Component
2889 (Comp_Type, Comp_Expr);
2891 -- If the component type does not in fact depend on
2892 -- discriminants, the subtype declaration is empty.
2894 if Present (Decl) then
2895 Append_To (L, Decl);
2896 Set_Etype (Comp_Expr, Defining_Entity (Decl));
2897 end if;
2898 end if;
2899 end;
2900 end if;
2901 end if;
2903 Instr :=
2904 Make_OK_Assignment_Statement (Loc,
2905 Name => Comp_Expr,
2906 Expression => Expr_Q);
2908 Set_No_Ctrl_Actions (Instr);
2909 Append_To (L, Instr);
2911 -- Adjust the tag if tagged (because of possible view
2912 -- conversions), unless compiling for a VM where tags are
2913 -- implicit.
2915 -- tmp.comp._tag := comp_typ'tag;
2917 if Is_Tagged_Type (Comp_Type)
2918 and then Tagged_Type_Expansion
2919 then
2920 Instr :=
2921 Make_OK_Assignment_Statement (Loc,
2922 Name =>
2923 Make_Selected_Component (Loc,
2924 Prefix => New_Copy_Tree (Comp_Expr),
2925 Selector_Name =>
2926 New_Occurrence_Of
2927 (First_Tag_Component (Comp_Type), Loc)),
2929 Expression =>
2930 Unchecked_Convert_To (RTE (RE_Tag),
2931 New_Occurrence_Of
2932 (Node (First_Elmt (Access_Disp_Table (Comp_Type))),
2933 Loc)));
2935 Append_To (L, Instr);
2936 end if;
2938 -- Generate:
2939 -- Adjust (tmp.comp);
2941 if Needs_Finalization (Comp_Type)
2942 and then not Is_Limited_Type (Comp_Type)
2943 then
2944 Append_To (L,
2945 Make_Adjust_Call
2946 (Obj_Ref => New_Copy_Tree (Comp_Expr),
2947 Typ => Comp_Type));
2948 end if;
2949 end if;
2951 -- comment would be good here ???
2953 elsif Ekind (Selector) = E_Discriminant
2954 and then Nkind (N) /= N_Extension_Aggregate
2955 and then Nkind (Parent (N)) = N_Component_Association
2956 and then Is_Constrained (Typ)
2957 then
2958 -- We must check that the discriminant value imposed by the
2959 -- context is the same as the value given in the subaggregate,
2960 -- because after the expansion into assignments there is no
2961 -- record on which to perform a regular discriminant check.
2963 declare
2964 D_Val : Elmt_Id;
2965 Disc : Entity_Id;
2967 begin
2968 D_Val := First_Elmt (Discriminant_Constraint (Typ));
2969 Disc := First_Discriminant (Typ);
2970 while Chars (Disc) /= Chars (Selector) loop
2971 Next_Discriminant (Disc);
2972 Next_Elmt (D_Val);
2973 end loop;
2975 pragma Assert (Present (D_Val));
2977 -- This check cannot performed for components that are
2978 -- constrained by a current instance, because this is not a
2979 -- value that can be compared with the actual constraint.
2981 if Nkind (Node (D_Val)) /= N_Attribute_Reference
2982 or else not Is_Entity_Name (Prefix (Node (D_Val)))
2983 or else not Is_Type (Entity (Prefix (Node (D_Val))))
2984 then
2985 Append_To (L,
2986 Make_Raise_Constraint_Error (Loc,
2987 Condition =>
2988 Make_Op_Ne (Loc,
2989 Left_Opnd => New_Copy_Tree (Node (D_Val)),
2990 Right_Opnd => Expression (Comp)),
2991 Reason => CE_Discriminant_Check_Failed));
2993 else
2994 -- Find self-reference in previous discriminant assignment,
2995 -- and replace with proper expression.
2997 declare
2998 Ass : Node_Id;
3000 begin
3001 Ass := First (L);
3002 while Present (Ass) loop
3003 if Nkind (Ass) = N_Assignment_Statement
3004 and then Nkind (Name (Ass)) = N_Selected_Component
3005 and then Chars (Selector_Name (Name (Ass))) =
3006 Chars (Disc)
3007 then
3008 Set_Expression
3009 (Ass, New_Copy_Tree (Expression (Comp)));
3010 exit;
3011 end if;
3012 Next (Ass);
3013 end loop;
3014 end;
3015 end if;
3016 end;
3017 end if;
3019 Next (Comp);
3020 end loop;
3022 -- If the type is tagged, the tag needs to be initialized (unless we
3023 -- are in VM-mode where tags are implicit). It is done late in the
3024 -- initialization process because in some cases, we call the init
3025 -- proc of an ancestor which will not leave out the right tag.
3027 if Ancestor_Is_Expression then
3028 null;
3030 -- For CPP types we generated a call to the C++ default constructor
3031 -- before the components have been initialized to ensure the proper
3032 -- initialization of the _Tag component (see above).
3034 elsif Is_CPP_Class (Typ) then
3035 null;
3037 elsif Is_Tagged_Type (Typ) and then Tagged_Type_Expansion then
3038 Instr :=
3039 Make_OK_Assignment_Statement (Loc,
3040 Name =>
3041 Make_Selected_Component (Loc,
3042 Prefix => New_Copy_Tree (Target),
3043 Selector_Name =>
3044 New_Occurrence_Of
3045 (First_Tag_Component (Base_Type (Typ)), Loc)),
3047 Expression =>
3048 Unchecked_Convert_To (RTE (RE_Tag),
3049 New_Occurrence_Of
3050 (Node (First_Elmt (Access_Disp_Table (Base_Type (Typ)))),
3051 Loc)));
3053 Append_To (L, Instr);
3055 -- Ada 2005 (AI-251): If the tagged type has been derived from an
3056 -- abstract interfaces we must also initialize the tags of the
3057 -- secondary dispatch tables.
3059 if Has_Interfaces (Base_Type (Typ)) then
3060 Init_Secondary_Tags
3061 (Typ => Base_Type (Typ),
3062 Target => Target,
3063 Stmts_List => L);
3064 end if;
3065 end if;
3067 -- If the controllers have not been initialized yet (by lack of non-
3068 -- discriminant components), let's do it now.
3070 Generate_Finalization_Actions;
3072 return L;
3073 end Build_Record_Aggr_Code;
3075 ---------------------------------------
3076 -- Collect_Initialization_Statements --
3077 ---------------------------------------
3079 procedure Collect_Initialization_Statements
3080 (Obj : Entity_Id;
3081 N : Node_Id;
3082 Node_After : Node_Id)
3084 Loc : constant Source_Ptr := Sloc (N);
3085 Init_Actions : constant List_Id := New_List;
3086 Init_Node : Node_Id;
3087 Comp_Stmt : Node_Id;
3089 begin
3090 -- Nothing to do if Obj is already frozen, as in this case we known we
3091 -- won't need to move the initialization statements about later on.
3093 if Is_Frozen (Obj) then
3094 return;
3095 end if;
3097 Init_Node := N;
3098 while Next (Init_Node) /= Node_After loop
3099 Append_To (Init_Actions, Remove_Next (Init_Node));
3100 end loop;
3102 if not Is_Empty_List (Init_Actions) then
3103 Comp_Stmt := Make_Compound_Statement (Loc, Actions => Init_Actions);
3104 Insert_Action_After (Init_Node, Comp_Stmt);
3105 Set_Initialization_Statements (Obj, Comp_Stmt);
3106 end if;
3107 end Collect_Initialization_Statements;
3109 -------------------------------
3110 -- Convert_Aggr_In_Allocator --
3111 -------------------------------
3113 procedure Convert_Aggr_In_Allocator
3114 (Alloc : Node_Id;
3115 Decl : Node_Id;
3116 Aggr : Node_Id)
3118 Loc : constant Source_Ptr := Sloc (Aggr);
3119 Typ : constant Entity_Id := Etype (Aggr);
3120 Temp : constant Entity_Id := Defining_Identifier (Decl);
3122 Occ : constant Node_Id :=
3123 Unchecked_Convert_To (Typ,
3124 Make_Explicit_Dereference (Loc, New_Occurrence_Of (Temp, Loc)));
3126 begin
3127 if Is_Array_Type (Typ) then
3128 Convert_Array_Aggr_In_Allocator (Decl, Aggr, Occ);
3130 elsif Has_Default_Init_Comps (Aggr) then
3131 declare
3132 L : constant List_Id := New_List;
3133 Init_Stmts : List_Id;
3135 begin
3136 Init_Stmts := Late_Expansion (Aggr, Typ, Occ);
3138 if Has_Task (Typ) then
3139 Build_Task_Allocate_Block_With_Init_Stmts (L, Aggr, Init_Stmts);
3140 Insert_Actions (Alloc, L);
3141 else
3142 Insert_Actions (Alloc, Init_Stmts);
3143 end if;
3144 end;
3146 else
3147 Insert_Actions (Alloc, Late_Expansion (Aggr, Typ, Occ));
3148 end if;
3149 end Convert_Aggr_In_Allocator;
3151 --------------------------------
3152 -- Convert_Aggr_In_Assignment --
3153 --------------------------------
3155 procedure Convert_Aggr_In_Assignment (N : Node_Id) is
3156 Aggr : Node_Id := Expression (N);
3157 Typ : constant Entity_Id := Etype (Aggr);
3158 Occ : constant Node_Id := New_Copy_Tree (Name (N));
3160 begin
3161 if Nkind (Aggr) = N_Qualified_Expression then
3162 Aggr := Expression (Aggr);
3163 end if;
3165 Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ));
3166 end Convert_Aggr_In_Assignment;
3168 ---------------------------------
3169 -- Convert_Aggr_In_Object_Decl --
3170 ---------------------------------
3172 procedure Convert_Aggr_In_Object_Decl (N : Node_Id) is
3173 Obj : constant Entity_Id := Defining_Identifier (N);
3174 Aggr : Node_Id := Expression (N);
3175 Loc : constant Source_Ptr := Sloc (Aggr);
3176 Typ : constant Entity_Id := Etype (Aggr);
3177 Occ : constant Node_Id := New_Occurrence_Of (Obj, Loc);
3179 function Discriminants_Ok return Boolean;
3180 -- If the object type is constrained, the discriminants in the
3181 -- aggregate must be checked against the discriminants of the subtype.
3182 -- This cannot be done using Apply_Discriminant_Checks because after
3183 -- expansion there is no aggregate left to check.
3185 ----------------------
3186 -- Discriminants_Ok --
3187 ----------------------
3189 function Discriminants_Ok return Boolean is
3190 Cond : Node_Id := Empty;
3191 Check : Node_Id;
3192 D : Entity_Id;
3193 Disc1 : Elmt_Id;
3194 Disc2 : Elmt_Id;
3195 Val1 : Node_Id;
3196 Val2 : Node_Id;
3198 begin
3199 D := First_Discriminant (Typ);
3200 Disc1 := First_Elmt (Discriminant_Constraint (Typ));
3201 Disc2 := First_Elmt (Discriminant_Constraint (Etype (Obj)));
3202 while Present (Disc1) and then Present (Disc2) loop
3203 Val1 := Node (Disc1);
3204 Val2 := Node (Disc2);
3206 if not Is_OK_Static_Expression (Val1)
3207 or else not Is_OK_Static_Expression (Val2)
3208 then
3209 Check := Make_Op_Ne (Loc,
3210 Left_Opnd => Duplicate_Subexpr (Val1),
3211 Right_Opnd => Duplicate_Subexpr (Val2));
3213 if No (Cond) then
3214 Cond := Check;
3216 else
3217 Cond := Make_Or_Else (Loc,
3218 Left_Opnd => Cond,
3219 Right_Opnd => Check);
3220 end if;
3222 elsif Expr_Value (Val1) /= Expr_Value (Val2) then
3223 Apply_Compile_Time_Constraint_Error (Aggr,
3224 Msg => "incorrect value for discriminant&??",
3225 Reason => CE_Discriminant_Check_Failed,
3226 Ent => D);
3227 return False;
3228 end if;
3230 Next_Discriminant (D);
3231 Next_Elmt (Disc1);
3232 Next_Elmt (Disc2);
3233 end loop;
3235 -- If any discriminant constraint is non-static, emit a check
3237 if Present (Cond) then
3238 Insert_Action (N,
3239 Make_Raise_Constraint_Error (Loc,
3240 Condition => Cond,
3241 Reason => CE_Discriminant_Check_Failed));
3242 end if;
3244 return True;
3245 end Discriminants_Ok;
3247 -- Start of processing for Convert_Aggr_In_Object_Decl
3249 begin
3250 Set_Assignment_OK (Occ);
3252 if Nkind (Aggr) = N_Qualified_Expression then
3253 Aggr := Expression (Aggr);
3254 end if;
3256 if Has_Discriminants (Typ)
3257 and then Typ /= Etype (Obj)
3258 and then Is_Constrained (Etype (Obj))
3259 and then not Discriminants_Ok
3260 then
3261 return;
3262 end if;
3264 -- If the context is an extended return statement, it has its own
3265 -- finalization machinery (i.e. works like a transient scope) and
3266 -- we do not want to create an additional one, because objects on
3267 -- the finalization list of the return must be moved to the caller's
3268 -- finalization list to complete the return.
3270 -- However, if the aggregate is limited, it is built in place, and the
3271 -- controlled components are not assigned to intermediate temporaries
3272 -- so there is no need for a transient scope in this case either.
3274 if Requires_Transient_Scope (Typ)
3275 and then Ekind (Current_Scope) /= E_Return_Statement
3276 and then not Is_Limited_Type (Typ)
3277 then
3278 Establish_Transient_Scope
3279 (Aggr,
3280 Sec_Stack =>
3281 Is_Controlled (Typ) or else Has_Controlled_Component (Typ));
3282 end if;
3284 declare
3285 Node_After : constant Node_Id := Next (N);
3286 begin
3287 Insert_Actions_After (N, Late_Expansion (Aggr, Typ, Occ));
3288 Collect_Initialization_Statements (Obj, N, Node_After);
3289 end;
3290 Set_No_Initialization (N);
3291 Initialize_Discriminants (N, Typ);
3292 end Convert_Aggr_In_Object_Decl;
3294 -------------------------------------
3295 -- Convert_Array_Aggr_In_Allocator --
3296 -------------------------------------
3298 procedure Convert_Array_Aggr_In_Allocator
3299 (Decl : Node_Id;
3300 Aggr : Node_Id;
3301 Target : Node_Id)
3303 Aggr_Code : List_Id;
3304 Typ : constant Entity_Id := Etype (Aggr);
3305 Ctyp : constant Entity_Id := Component_Type (Typ);
3307 begin
3308 -- The target is an explicit dereference of the allocated object.
3309 -- Generate component assignments to it, as for an aggregate that
3310 -- appears on the right-hand side of an assignment statement.
3312 Aggr_Code :=
3313 Build_Array_Aggr_Code (Aggr,
3314 Ctype => Ctyp,
3315 Index => First_Index (Typ),
3316 Into => Target,
3317 Scalar_Comp => Is_Scalar_Type (Ctyp));
3319 Insert_Actions_After (Decl, Aggr_Code);
3320 end Convert_Array_Aggr_In_Allocator;
3322 ----------------------------
3323 -- Convert_To_Assignments --
3324 ----------------------------
3326 procedure Convert_To_Assignments (N : Node_Id; Typ : Entity_Id) is
3327 Loc : constant Source_Ptr := Sloc (N);
3328 T : Entity_Id;
3329 Temp : Entity_Id;
3331 Aggr_Code : List_Id;
3332 Instr : Node_Id;
3333 Target_Expr : Node_Id;
3334 Parent_Kind : Node_Kind;
3335 Unc_Decl : Boolean := False;
3336 Parent_Node : Node_Id;
3338 begin
3339 pragma Assert (not Is_Static_Dispatch_Table_Aggregate (N));
3340 pragma Assert (Is_Record_Type (Typ));
3342 Parent_Node := Parent (N);
3343 Parent_Kind := Nkind (Parent_Node);
3345 if Parent_Kind = N_Qualified_Expression then
3347 -- Check if we are in a unconstrained declaration because in this
3348 -- case the current delayed expansion mechanism doesn't work when
3349 -- the declared object size depend on the initializing expr.
3351 begin
3352 Parent_Node := Parent (Parent_Node);
3353 Parent_Kind := Nkind (Parent_Node);
3355 if Parent_Kind = N_Object_Declaration then
3356 Unc_Decl :=
3357 not Is_Entity_Name (Object_Definition (Parent_Node))
3358 or else Has_Discriminants
3359 (Entity (Object_Definition (Parent_Node)))
3360 or else Is_Class_Wide_Type
3361 (Entity (Object_Definition (Parent_Node)));
3362 end if;
3363 end;
3364 end if;
3366 -- Just set the Delay flag in the cases where the transformation will be
3367 -- done top down from above.
3369 if False
3371 -- Internal aggregate (transformed when expanding the parent)
3373 or else Parent_Kind = N_Aggregate
3374 or else Parent_Kind = N_Extension_Aggregate
3375 or else Parent_Kind = N_Component_Association
3377 -- Allocator (see Convert_Aggr_In_Allocator)
3379 or else Parent_Kind = N_Allocator
3381 -- Object declaration (see Convert_Aggr_In_Object_Decl)
3383 or else (Parent_Kind = N_Object_Declaration and then not Unc_Decl)
3385 -- Safe assignment (see Convert_Aggr_Assignments). So far only the
3386 -- assignments in init procs are taken into account.
3388 or else (Parent_Kind = N_Assignment_Statement
3389 and then Inside_Init_Proc)
3391 -- (Ada 2005) An inherently limited type in a return statement, which
3392 -- will be handled in a build-in-place fashion, and may be rewritten
3393 -- as an extended return and have its own finalization machinery.
3394 -- In the case of a simple return, the aggregate needs to be delayed
3395 -- until the scope for the return statement has been created, so
3396 -- that any finalization chain will be associated with that scope.
3397 -- For extended returns, we delay expansion to avoid the creation
3398 -- of an unwanted transient scope that could result in premature
3399 -- finalization of the return object (which is built in in place
3400 -- within the caller's scope).
3402 or else
3403 (Is_Limited_View (Typ)
3404 and then
3405 (Nkind (Parent (Parent_Node)) = N_Extended_Return_Statement
3406 or else Nkind (Parent_Node) = N_Simple_Return_Statement))
3407 then
3408 Set_Expansion_Delayed (N);
3409 return;
3410 end if;
3412 if Requires_Transient_Scope (Typ) then
3413 Establish_Transient_Scope (N, Sec_Stack => Needs_Finalization (Typ));
3414 end if;
3416 -- If the aggregate is non-limited, create a temporary. If it is limited
3417 -- and context is an assignment, this is a subaggregate for an enclosing
3418 -- aggregate being expanded. It must be built in place, so use target of
3419 -- the current assignment.
3421 if Is_Limited_Type (Typ)
3422 and then Nkind (Parent (N)) = N_Assignment_Statement
3423 then
3424 Target_Expr := New_Copy_Tree (Name (Parent (N)));
3425 Insert_Actions (Parent (N),
3426 Build_Record_Aggr_Code (N, Typ, Target_Expr));
3427 Rewrite (Parent (N), Make_Null_Statement (Loc));
3429 else
3430 Temp := Make_Temporary (Loc, 'A', N);
3432 -- If the type inherits unknown discriminants, use the view with
3433 -- known discriminants if available.
3435 if Has_Unknown_Discriminants (Typ)
3436 and then Present (Underlying_Record_View (Typ))
3437 then
3438 T := Underlying_Record_View (Typ);
3439 else
3440 T := Typ;
3441 end if;
3443 Instr :=
3444 Make_Object_Declaration (Loc,
3445 Defining_Identifier => Temp,
3446 Object_Definition => New_Occurrence_Of (T, Loc));
3448 Set_No_Initialization (Instr);
3449 Insert_Action (N, Instr);
3450 Initialize_Discriminants (Instr, T);
3452 Target_Expr := New_Occurrence_Of (Temp, Loc);
3453 Aggr_Code := Build_Record_Aggr_Code (N, T, Target_Expr);
3455 -- Save the last assignment statement associated with the aggregate
3456 -- when building a controlled object. This reference is utilized by
3457 -- the finalization machinery when marking an object as successfully
3458 -- initialized.
3460 if Needs_Finalization (T) then
3461 Set_Last_Aggregate_Assignment (Temp, Last (Aggr_Code));
3462 end if;
3464 Insert_Actions (N, Aggr_Code);
3465 Rewrite (N, New_Occurrence_Of (Temp, Loc));
3466 Analyze_And_Resolve (N, T);
3467 end if;
3468 end Convert_To_Assignments;
3470 ---------------------------
3471 -- Convert_To_Positional --
3472 ---------------------------
3474 procedure Convert_To_Positional
3475 (N : Node_Id;
3476 Max_Others_Replicate : Nat := 5;
3477 Handle_Bit_Packed : Boolean := False)
3479 Typ : constant Entity_Id := Etype (N);
3481 Static_Components : Boolean := True;
3483 procedure Check_Static_Components;
3484 -- Check whether all components of the aggregate are compile-time known
3485 -- values, and can be passed as is to the back-end without further
3486 -- expansion.
3488 function Flatten
3489 (N : Node_Id;
3490 Ix : Node_Id;
3491 Ixb : Node_Id) return Boolean;
3492 -- Convert the aggregate into a purely positional form if possible. On
3493 -- entry the bounds of all dimensions are known to be static, and the
3494 -- total number of components is safe enough to expand.
3496 function Is_Flat (N : Node_Id; Dims : Int) return Boolean;
3497 -- Return True iff the array N is flat (which is not trivial in the case
3498 -- of multidimensional aggregates).
3500 -----------------------------
3501 -- Check_Static_Components --
3502 -----------------------------
3504 -- Could use some comments in this body ???
3506 procedure Check_Static_Components is
3507 Expr : Node_Id;
3509 begin
3510 Static_Components := True;
3512 if Nkind (N) = N_String_Literal then
3513 null;
3515 elsif Present (Expressions (N)) then
3516 Expr := First (Expressions (N));
3517 while Present (Expr) loop
3518 if Nkind (Expr) /= N_Aggregate
3519 or else not Compile_Time_Known_Aggregate (Expr)
3520 or else Expansion_Delayed (Expr)
3521 then
3522 Static_Components := False;
3523 exit;
3524 end if;
3526 Next (Expr);
3527 end loop;
3528 end if;
3530 if Nkind (N) = N_Aggregate
3531 and then Present (Component_Associations (N))
3532 then
3533 Expr := First (Component_Associations (N));
3534 while Present (Expr) loop
3535 if Nkind_In (Expression (Expr), N_Integer_Literal,
3536 N_Real_Literal)
3537 then
3538 null;
3540 elsif Is_Entity_Name (Expression (Expr))
3541 and then Present (Entity (Expression (Expr)))
3542 and then Ekind (Entity (Expression (Expr))) =
3543 E_Enumeration_Literal
3544 then
3545 null;
3547 elsif Nkind (Expression (Expr)) /= N_Aggregate
3548 or else not Compile_Time_Known_Aggregate (Expression (Expr))
3549 or else Expansion_Delayed (Expression (Expr))
3550 then
3551 Static_Components := False;
3552 exit;
3553 end if;
3555 Next (Expr);
3556 end loop;
3557 end if;
3558 end Check_Static_Components;
3560 -------------
3561 -- Flatten --
3562 -------------
3564 function Flatten
3565 (N : Node_Id;
3566 Ix : Node_Id;
3567 Ixb : Node_Id) return Boolean
3569 Loc : constant Source_Ptr := Sloc (N);
3570 Blo : constant Node_Id := Type_Low_Bound (Etype (Ixb));
3571 Lo : constant Node_Id := Type_Low_Bound (Etype (Ix));
3572 Hi : constant Node_Id := Type_High_Bound (Etype (Ix));
3573 Lov : Uint;
3574 Hiv : Uint;
3576 Others_Present : Boolean := False;
3578 begin
3579 if Nkind (Original_Node (N)) = N_String_Literal then
3580 return True;
3581 end if;
3583 if not Compile_Time_Known_Value (Lo)
3584 or else not Compile_Time_Known_Value (Hi)
3585 then
3586 return False;
3587 end if;
3589 Lov := Expr_Value (Lo);
3590 Hiv := Expr_Value (Hi);
3592 -- Check if there is an others choice
3594 if Present (Component_Associations (N)) then
3595 declare
3596 Assoc : Node_Id;
3597 Choice : Node_Id;
3599 begin
3600 Assoc := First (Component_Associations (N));
3601 while Present (Assoc) loop
3603 -- If this is a box association, flattening is in general
3604 -- not possible because at this point we cannot tell if the
3605 -- default is static or even exists.
3607 if Box_Present (Assoc) then
3608 return False;
3609 end if;
3611 Choice := First (Choices (Assoc));
3613 while Present (Choice) loop
3614 if Nkind (Choice) = N_Others_Choice then
3615 Others_Present := True;
3616 end if;
3618 Next (Choice);
3619 end loop;
3621 Next (Assoc);
3622 end loop;
3623 end;
3624 end if;
3626 -- If the low bound is not known at compile time and others is not
3627 -- present we can proceed since the bounds can be obtained from the
3628 -- aggregate.
3630 -- Note: This case is required in VM platforms since their backends
3631 -- normalize array indexes in the range 0 .. N-1. Hence, if we do
3632 -- not flat an array whose bounds cannot be obtained from the type
3633 -- of the index the backend has no way to properly generate the code.
3634 -- See ACATS c460010 for an example.
3636 if Hiv < Lov
3637 or else (not Compile_Time_Known_Value (Blo) and then Others_Present)
3638 then
3639 return False;
3640 end if;
3642 -- Determine if set of alternatives is suitable for conversion and
3643 -- build an array containing the values in sequence.
3645 declare
3646 Vals : array (UI_To_Int (Lov) .. UI_To_Int (Hiv))
3647 of Node_Id := (others => Empty);
3648 -- The values in the aggregate sorted appropriately
3650 Vlist : List_Id;
3651 -- Same data as Vals in list form
3653 Rep_Count : Nat;
3654 -- Used to validate Max_Others_Replicate limit
3656 Elmt : Node_Id;
3657 Num : Int := UI_To_Int (Lov);
3658 Choice_Index : Int;
3659 Choice : Node_Id;
3660 Lo, Hi : Node_Id;
3662 begin
3663 if Present (Expressions (N)) then
3664 Elmt := First (Expressions (N));
3665 while Present (Elmt) loop
3666 if Nkind (Elmt) = N_Aggregate
3667 and then Present (Next_Index (Ix))
3668 and then
3669 not Flatten (Elmt, Next_Index (Ix), Next_Index (Ixb))
3670 then
3671 return False;
3672 end if;
3674 Vals (Num) := Relocate_Node (Elmt);
3675 Num := Num + 1;
3677 Next (Elmt);
3678 end loop;
3679 end if;
3681 if No (Component_Associations (N)) then
3682 return True;
3683 end if;
3685 Elmt := First (Component_Associations (N));
3687 if Nkind (Expression (Elmt)) = N_Aggregate then
3688 if Present (Next_Index (Ix))
3689 and then
3690 not Flatten
3691 (Expression (Elmt), Next_Index (Ix), Next_Index (Ixb))
3692 then
3693 return False;
3694 end if;
3695 end if;
3697 Component_Loop : while Present (Elmt) loop
3698 Choice := First (Choices (Elmt));
3699 Choice_Loop : while Present (Choice) loop
3701 -- If we have an others choice, fill in the missing elements
3702 -- subject to the limit established by Max_Others_Replicate.
3704 if Nkind (Choice) = N_Others_Choice then
3705 Rep_Count := 0;
3707 for J in Vals'Range loop
3708 if No (Vals (J)) then
3709 Vals (J) := New_Copy_Tree (Expression (Elmt));
3710 Rep_Count := Rep_Count + 1;
3712 -- Check for maximum others replication. Note that
3713 -- we skip this test if either of the restrictions
3714 -- No_Elaboration_Code or No_Implicit_Loops is
3715 -- active, if this is a preelaborable unit or
3716 -- a predefined unit, or if the unit must be
3717 -- placed in data memory. This also ensures that
3718 -- predefined units get the same level of constant
3719 -- folding in Ada 95 and Ada 2005, where their
3720 -- categorization has changed.
3722 declare
3723 P : constant Entity_Id :=
3724 Cunit_Entity (Current_Sem_Unit);
3726 begin
3727 -- Check if duplication OK and if so continue
3728 -- processing.
3730 if Restriction_Active (No_Elaboration_Code)
3731 or else Restriction_Active (No_Implicit_Loops)
3732 or else
3733 (Ekind (Current_Scope) = E_Package
3734 and then Static_Elaboration_Desired
3735 (Current_Scope))
3736 or else Is_Preelaborated (P)
3737 or else (Ekind (P) = E_Package_Body
3738 and then
3739 Is_Preelaborated (Spec_Entity (P)))
3740 or else
3741 Is_Predefined_File_Name
3742 (Unit_File_Name (Get_Source_Unit (P)))
3743 then
3744 null;
3746 -- If duplication not OK, then we return False
3747 -- if the replication count is too high
3749 elsif Rep_Count > Max_Others_Replicate then
3750 return False;
3752 -- Continue on if duplication not OK, but the
3753 -- replication count is not excessive.
3755 else
3756 null;
3757 end if;
3758 end;
3759 end if;
3760 end loop;
3762 exit Component_Loop;
3764 -- Case of a subtype mark, identifier or expanded name
3766 elsif Is_Entity_Name (Choice)
3767 and then Is_Type (Entity (Choice))
3768 then
3769 Lo := Type_Low_Bound (Etype (Choice));
3770 Hi := Type_High_Bound (Etype (Choice));
3772 -- Case of subtype indication
3774 elsif Nkind (Choice) = N_Subtype_Indication then
3775 Lo := Low_Bound (Range_Expression (Constraint (Choice)));
3776 Hi := High_Bound (Range_Expression (Constraint (Choice)));
3778 -- Case of a range
3780 elsif Nkind (Choice) = N_Range then
3781 Lo := Low_Bound (Choice);
3782 Hi := High_Bound (Choice);
3784 -- Normal subexpression case
3786 else pragma Assert (Nkind (Choice) in N_Subexpr);
3787 if not Compile_Time_Known_Value (Choice) then
3788 return False;
3790 else
3791 Choice_Index := UI_To_Int (Expr_Value (Choice));
3793 if Choice_Index in Vals'Range then
3794 Vals (Choice_Index) :=
3795 New_Copy_Tree (Expression (Elmt));
3796 goto Continue;
3798 -- Choice is statically out-of-range, will be
3799 -- rewritten to raise Constraint_Error.
3801 else
3802 return False;
3803 end if;
3804 end if;
3805 end if;
3807 -- Range cases merge with Lo,Hi set
3809 if not Compile_Time_Known_Value (Lo)
3810 or else
3811 not Compile_Time_Known_Value (Hi)
3812 then
3813 return False;
3815 else
3816 for J in UI_To_Int (Expr_Value (Lo)) ..
3817 UI_To_Int (Expr_Value (Hi))
3818 loop
3819 Vals (J) := New_Copy_Tree (Expression (Elmt));
3820 end loop;
3821 end if;
3823 <<Continue>>
3824 Next (Choice);
3825 end loop Choice_Loop;
3827 Next (Elmt);
3828 end loop Component_Loop;
3830 -- If we get here the conversion is possible
3832 Vlist := New_List;
3833 for J in Vals'Range loop
3834 Append (Vals (J), Vlist);
3835 end loop;
3837 Rewrite (N, Make_Aggregate (Loc, Expressions => Vlist));
3838 Set_Aggregate_Bounds (N, Aggregate_Bounds (Original_Node (N)));
3839 return True;
3840 end;
3841 end Flatten;
3843 -------------
3844 -- Is_Flat --
3845 -------------
3847 function Is_Flat (N : Node_Id; Dims : Int) return Boolean is
3848 Elmt : Node_Id;
3850 begin
3851 if Dims = 0 then
3852 return True;
3854 elsif Nkind (N) = N_Aggregate then
3855 if Present (Component_Associations (N)) then
3856 return False;
3858 else
3859 Elmt := First (Expressions (N));
3860 while Present (Elmt) loop
3861 if not Is_Flat (Elmt, Dims - 1) then
3862 return False;
3863 end if;
3865 Next (Elmt);
3866 end loop;
3868 return True;
3869 end if;
3870 else
3871 return True;
3872 end if;
3873 end Is_Flat;
3875 -- Start of processing for Convert_To_Positional
3877 begin
3878 -- Ada 2005 (AI-287): Do not convert in case of default initialized
3879 -- components because in this case will need to call the corresponding
3880 -- IP procedure.
3882 if Has_Default_Init_Comps (N) then
3883 return;
3884 end if;
3886 if Is_Flat (N, Number_Dimensions (Typ)) then
3887 return;
3888 end if;
3890 if Is_Bit_Packed_Array (Typ) and then not Handle_Bit_Packed then
3891 return;
3892 end if;
3894 -- Do not convert to positional if controlled components are involved
3895 -- since these require special processing
3897 if Has_Controlled_Component (Typ) then
3898 return;
3899 end if;
3901 Check_Static_Components;
3903 -- If the size is known, or all the components are static, try to
3904 -- build a fully positional aggregate.
3906 -- The size of the type may not be known for an aggregate with
3907 -- discriminated array components, but if the components are static
3908 -- it is still possible to verify statically that the length is
3909 -- compatible with the upper bound of the type, and therefore it is
3910 -- worth flattening such aggregates as well.
3912 -- For now the back-end expands these aggregates into individual
3913 -- assignments to the target anyway, but it is conceivable that
3914 -- it will eventually be able to treat such aggregates statically???
3916 if Aggr_Size_OK (N, Typ)
3917 and then Flatten (N, First_Index (Typ), First_Index (Base_Type (Typ)))
3918 then
3919 if Static_Components then
3920 Set_Compile_Time_Known_Aggregate (N);
3921 Set_Expansion_Delayed (N, False);
3922 end if;
3924 Analyze_And_Resolve (N, Typ);
3925 end if;
3927 -- Is Static_Eaboration_Desired has been specified, diagnose aggregates
3928 -- that will still require initialization code.
3930 if (Ekind (Current_Scope) = E_Package
3931 and then Static_Elaboration_Desired (Current_Scope))
3932 and then Nkind (Parent (N)) = N_Object_Declaration
3933 then
3934 declare
3935 Expr : Node_Id;
3937 begin
3938 if Nkind (N) = N_Aggregate and then Present (Expressions (N)) then
3939 Expr := First (Expressions (N));
3940 while Present (Expr) loop
3941 if Nkind_In (Expr, N_Integer_Literal, N_Real_Literal)
3942 or else
3943 (Is_Entity_Name (Expr)
3944 and then Ekind (Entity (Expr)) = E_Enumeration_Literal)
3945 then
3946 null;
3948 else
3949 Error_Msg_N
3950 ("non-static object requires elaboration code??", N);
3951 exit;
3952 end if;
3954 Next (Expr);
3955 end loop;
3957 if Present (Component_Associations (N)) then
3958 Error_Msg_N ("object requires elaboration code??", N);
3959 end if;
3960 end if;
3961 end;
3962 end if;
3963 end Convert_To_Positional;
3965 ----------------------------
3966 -- Expand_Array_Aggregate --
3967 ----------------------------
3969 -- Array aggregate expansion proceeds as follows:
3971 -- 1. If requested we generate code to perform all the array aggregate
3972 -- bound checks, specifically
3974 -- (a) Check that the index range defined by aggregate bounds is
3975 -- compatible with corresponding index subtype.
3977 -- (b) If an others choice is present check that no aggregate
3978 -- index is outside the bounds of the index constraint.
3980 -- (c) For multidimensional arrays make sure that all subaggregates
3981 -- corresponding to the same dimension have the same bounds.
3983 -- 2. Check for packed array aggregate which can be converted to a
3984 -- constant so that the aggregate disappears completely.
3986 -- 3. Check case of nested aggregate. Generally nested aggregates are
3987 -- handled during the processing of the parent aggregate.
3989 -- 4. Check if the aggregate can be statically processed. If this is the
3990 -- case pass it as is to Gigi. Note that a necessary condition for
3991 -- static processing is that the aggregate be fully positional.
3993 -- 5. If in place aggregate expansion is possible (i.e. no need to create
3994 -- a temporary) then mark the aggregate as such and return. Otherwise
3995 -- create a new temporary and generate the appropriate initialization
3996 -- code.
3998 procedure Expand_Array_Aggregate (N : Node_Id) is
3999 Loc : constant Source_Ptr := Sloc (N);
4001 Typ : constant Entity_Id := Etype (N);
4002 Ctyp : constant Entity_Id := Component_Type (Typ);
4003 -- Typ is the correct constrained array subtype of the aggregate
4004 -- Ctyp is the corresponding component type.
4006 Aggr_Dimension : constant Pos := Number_Dimensions (Typ);
4007 -- Number of aggregate index dimensions
4009 Aggr_Low : array (1 .. Aggr_Dimension) of Node_Id;
4010 Aggr_High : array (1 .. Aggr_Dimension) of Node_Id;
4011 -- Low and High bounds of the constraint for each aggregate index
4013 Aggr_Index_Typ : array (1 .. Aggr_Dimension) of Entity_Id;
4014 -- The type of each index
4016 In_Place_Assign_OK_For_Declaration : Boolean := False;
4017 -- True if we are to generate an in place assignment for a declaration
4019 Maybe_In_Place_OK : Boolean;
4020 -- If the type is neither controlled nor packed and the aggregate
4021 -- is the expression in an assignment, assignment in place may be
4022 -- possible, provided other conditions are met on the LHS.
4024 Others_Present : array (1 .. Aggr_Dimension) of Boolean :=
4025 (others => False);
4026 -- If Others_Present (J) is True, then there is an others choice
4027 -- in one of the sub-aggregates of N at dimension J.
4029 function Aggr_Assignment_OK_For_Backend (N : Node_Id) return Boolean;
4030 -- Returns true if an aggregate assignment can be done by the back end
4032 procedure Build_Constrained_Type (Positional : Boolean);
4033 -- If the subtype is not static or unconstrained, build a constrained
4034 -- type using the computable sizes of the aggregate and its sub-
4035 -- aggregates.
4037 procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id);
4038 -- Checks that the bounds of Aggr_Bounds are within the bounds defined
4039 -- by Index_Bounds.
4041 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos);
4042 -- Checks that in a multi-dimensional array aggregate all subaggregates
4043 -- corresponding to the same dimension have the same bounds.
4044 -- Sub_Aggr is an array sub-aggregate. Dim is the dimension
4045 -- corresponding to the sub-aggregate.
4047 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos);
4048 -- Computes the values of array Others_Present. Sub_Aggr is the
4049 -- array sub-aggregate we start the computation from. Dim is the
4050 -- dimension corresponding to the sub-aggregate.
4052 function In_Place_Assign_OK return Boolean;
4053 -- Simple predicate to determine whether an aggregate assignment can
4054 -- be done in place, because none of the new values can depend on the
4055 -- components of the target of the assignment.
4057 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos);
4058 -- Checks that if an others choice is present in any sub-aggregate no
4059 -- aggregate index is outside the bounds of the index constraint.
4060 -- Sub_Aggr is an array sub-aggregate. Dim is the dimension
4061 -- corresponding to the sub-aggregate.
4063 function Safe_Left_Hand_Side (N : Node_Id) return Boolean;
4064 -- In addition to Maybe_In_Place_OK, in order for an aggregate to be
4065 -- built directly into the target of the assignment it must be free
4066 -- of side-effects.
4068 ------------------------------------
4069 -- Aggr_Assignment_OK_For_Backend --
4070 ------------------------------------
4072 -- Backend processing by Gigi/gcc is possible only if all the following
4073 -- conditions are met:
4075 -- 1. N consists of a single OTHERS choice, possibly recursively
4077 -- 2. The array type is not packed
4079 -- 3. The array type has no atomic components
4081 -- 4. The array type has no null ranges (the purpose of this is to
4082 -- avoid a bogus warning for an out-of-range value).
4084 -- 5. The component type is discrete
4086 -- 6. The component size is Storage_Unit or the value is of the form
4087 -- M * (1 + A**1 + A**2 + .. A**(K-1)) where A = 2**(Storage_Unit)
4088 -- and M in 1 .. A-1. This can also be viewed as K occurrences of
4089 -- the 8-bit value M, concatenated together.
4091 -- The ultimate goal is to generate a call to a fast memset routine
4092 -- specifically optimized for the target.
4094 function Aggr_Assignment_OK_For_Backend (N : Node_Id) return Boolean is
4095 Ctyp : Entity_Id;
4096 Index : Entity_Id;
4097 Expr : Node_Id := N;
4098 Low : Node_Id;
4099 High : Node_Id;
4100 Remainder : Uint;
4101 Value : Uint;
4102 Nunits : Nat;
4104 begin
4105 -- Recurse as far as possible to find the innermost component type
4107 Ctyp := Etype (N);
4108 while Is_Array_Type (Ctyp) loop
4109 if Nkind (Expr) /= N_Aggregate
4110 or else not Is_Others_Aggregate (Expr)
4111 then
4112 return False;
4113 end if;
4115 if Present (Packed_Array_Impl_Type (Ctyp)) then
4116 return False;
4117 end if;
4119 if Has_Atomic_Components (Ctyp) then
4120 return False;
4121 end if;
4123 Index := First_Index (Ctyp);
4124 while Present (Index) loop
4125 Get_Index_Bounds (Index, Low, High);
4127 if Is_Null_Range (Low, High) then
4128 return False;
4129 end if;
4131 Next_Index (Index);
4132 end loop;
4134 Expr := Expression (First (Component_Associations (Expr)));
4136 for J in 1 .. Number_Dimensions (Ctyp) - 1 loop
4137 if Nkind (Expr) /= N_Aggregate
4138 or else not Is_Others_Aggregate (Expr)
4139 then
4140 return False;
4141 end if;
4143 Expr := Expression (First (Component_Associations (Expr)));
4144 end loop;
4146 Ctyp := Component_Type (Ctyp);
4148 if Is_Atomic (Ctyp) then
4149 return False;
4150 end if;
4151 end loop;
4153 if not Is_Discrete_Type (Ctyp) then
4154 return False;
4155 end if;
4157 -- The expression needs to be analyzed if True is returned
4159 Analyze_And_Resolve (Expr, Ctyp);
4161 -- The back end uses the Esize as the precision of the type
4163 Nunits := UI_To_Int (Esize (Ctyp)) / System_Storage_Unit;
4165 if Nunits = 1 then
4166 return True;
4167 end if;
4169 if not Compile_Time_Known_Value (Expr) then
4170 return False;
4171 end if;
4173 Value := Expr_Value (Expr);
4175 if Has_Biased_Representation (Ctyp) then
4176 Value := Value - Expr_Value (Type_Low_Bound (Ctyp));
4177 end if;
4179 -- Values 0 and -1 immediately satisfy the last check
4181 if Value = Uint_0 or else Value = Uint_Minus_1 then
4182 return True;
4183 end if;
4185 -- We need to work with an unsigned value
4187 if Value < 0 then
4188 Value := Value + 2**(System_Storage_Unit * Nunits);
4189 end if;
4191 Remainder := Value rem 2**System_Storage_Unit;
4193 for J in 1 .. Nunits - 1 loop
4194 Value := Value / 2**System_Storage_Unit;
4196 if Value rem 2**System_Storage_Unit /= Remainder then
4197 return False;
4198 end if;
4199 end loop;
4201 return True;
4202 end Aggr_Assignment_OK_For_Backend;
4204 ----------------------------
4205 -- Build_Constrained_Type --
4206 ----------------------------
4208 procedure Build_Constrained_Type (Positional : Boolean) is
4209 Loc : constant Source_Ptr := Sloc (N);
4210 Agg_Type : constant Entity_Id := Make_Temporary (Loc, 'A');
4211 Comp : Node_Id;
4212 Decl : Node_Id;
4213 Typ : constant Entity_Id := Etype (N);
4214 Indexes : constant List_Id := New_List;
4215 Num : Int;
4216 Sub_Agg : Node_Id;
4218 begin
4219 -- If the aggregate is purely positional, all its subaggregates
4220 -- have the same size. We collect the dimensions from the first
4221 -- subaggregate at each level.
4223 if Positional then
4224 Sub_Agg := N;
4226 for D in 1 .. Number_Dimensions (Typ) loop
4227 Sub_Agg := First (Expressions (Sub_Agg));
4229 Comp := Sub_Agg;
4230 Num := 0;
4231 while Present (Comp) loop
4232 Num := Num + 1;
4233 Next (Comp);
4234 end loop;
4236 Append_To (Indexes,
4237 Make_Range (Loc,
4238 Low_Bound => Make_Integer_Literal (Loc, 1),
4239 High_Bound => Make_Integer_Literal (Loc, Num)));
4240 end loop;
4242 else
4243 -- We know the aggregate type is unconstrained and the aggregate
4244 -- is not processable by the back end, therefore not necessarily
4245 -- positional. Retrieve each dimension bounds (computed earlier).
4247 for D in 1 .. Number_Dimensions (Typ) loop
4248 Append_To (Indexes,
4249 Make_Range (Loc,
4250 Low_Bound => Aggr_Low (D),
4251 High_Bound => Aggr_High (D)));
4252 end loop;
4253 end if;
4255 Decl :=
4256 Make_Full_Type_Declaration (Loc,
4257 Defining_Identifier => Agg_Type,
4258 Type_Definition =>
4259 Make_Constrained_Array_Definition (Loc,
4260 Discrete_Subtype_Definitions => Indexes,
4261 Component_Definition =>
4262 Make_Component_Definition (Loc,
4263 Aliased_Present => False,
4264 Subtype_Indication =>
4265 New_Occurrence_Of (Component_Type (Typ), Loc))));
4267 Insert_Action (N, Decl);
4268 Analyze (Decl);
4269 Set_Etype (N, Agg_Type);
4270 Set_Is_Itype (Agg_Type);
4271 Freeze_Itype (Agg_Type, N);
4272 end Build_Constrained_Type;
4274 ------------------
4275 -- Check_Bounds --
4276 ------------------
4278 procedure Check_Bounds (Aggr_Bounds : Node_Id; Index_Bounds : Node_Id) is
4279 Aggr_Lo : Node_Id;
4280 Aggr_Hi : Node_Id;
4282 Ind_Lo : Node_Id;
4283 Ind_Hi : Node_Id;
4285 Cond : Node_Id := Empty;
4287 begin
4288 Get_Index_Bounds (Aggr_Bounds, Aggr_Lo, Aggr_Hi);
4289 Get_Index_Bounds (Index_Bounds, Ind_Lo, Ind_Hi);
4291 -- Generate the following test:
4293 -- [constraint_error when
4294 -- Aggr_Lo <= Aggr_Hi and then
4295 -- (Aggr_Lo < Ind_Lo or else Aggr_Hi > Ind_Hi)]
4297 -- As an optimization try to see if some tests are trivially vacuous
4298 -- because we are comparing an expression against itself.
4300 if Aggr_Lo = Ind_Lo and then Aggr_Hi = Ind_Hi then
4301 Cond := Empty;
4303 elsif Aggr_Hi = Ind_Hi then
4304 Cond :=
4305 Make_Op_Lt (Loc,
4306 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4307 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Lo));
4309 elsif Aggr_Lo = Ind_Lo then
4310 Cond :=
4311 Make_Op_Gt (Loc,
4312 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi),
4313 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Hi));
4315 else
4316 Cond :=
4317 Make_Or_Else (Loc,
4318 Left_Opnd =>
4319 Make_Op_Lt (Loc,
4320 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4321 Right_Opnd => Duplicate_Subexpr_Move_Checks (Ind_Lo)),
4323 Right_Opnd =>
4324 Make_Op_Gt (Loc,
4325 Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
4326 Right_Opnd => Duplicate_Subexpr (Ind_Hi)));
4327 end if;
4329 if Present (Cond) then
4330 Cond :=
4331 Make_And_Then (Loc,
4332 Left_Opnd =>
4333 Make_Op_Le (Loc,
4334 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4335 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi)),
4337 Right_Opnd => Cond);
4339 Set_Analyzed (Left_Opnd (Left_Opnd (Cond)), False);
4340 Set_Analyzed (Right_Opnd (Left_Opnd (Cond)), False);
4341 Insert_Action (N,
4342 Make_Raise_Constraint_Error (Loc,
4343 Condition => Cond,
4344 Reason => CE_Range_Check_Failed));
4345 end if;
4346 end Check_Bounds;
4348 ----------------------------
4349 -- Check_Same_Aggr_Bounds --
4350 ----------------------------
4352 procedure Check_Same_Aggr_Bounds (Sub_Aggr : Node_Id; Dim : Pos) is
4353 Sub_Lo : constant Node_Id := Low_Bound (Aggregate_Bounds (Sub_Aggr));
4354 Sub_Hi : constant Node_Id := High_Bound (Aggregate_Bounds (Sub_Aggr));
4355 -- The bounds of this specific sub-aggregate
4357 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
4358 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
4359 -- The bounds of the aggregate for this dimension
4361 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
4362 -- The index type for this dimension.xxx
4364 Cond : Node_Id := Empty;
4365 Assoc : Node_Id;
4366 Expr : Node_Id;
4368 begin
4369 -- If index checks are on generate the test
4371 -- [constraint_error when
4372 -- Aggr_Lo /= Sub_Lo or else Aggr_Hi /= Sub_Hi]
4374 -- As an optimization try to see if some tests are trivially vacuos
4375 -- because we are comparing an expression against itself. Also for
4376 -- the first dimension the test is trivially vacuous because there
4377 -- is just one aggregate for dimension 1.
4379 if Index_Checks_Suppressed (Ind_Typ) then
4380 Cond := Empty;
4382 elsif Dim = 1 or else (Aggr_Lo = Sub_Lo and then Aggr_Hi = Sub_Hi)
4383 then
4384 Cond := Empty;
4386 elsif Aggr_Hi = Sub_Hi then
4387 Cond :=
4388 Make_Op_Ne (Loc,
4389 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4390 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo));
4392 elsif Aggr_Lo = Sub_Lo then
4393 Cond :=
4394 Make_Op_Ne (Loc,
4395 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Hi),
4396 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Hi));
4398 else
4399 Cond :=
4400 Make_Or_Else (Loc,
4401 Left_Opnd =>
4402 Make_Op_Ne (Loc,
4403 Left_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo),
4404 Right_Opnd => Duplicate_Subexpr_Move_Checks (Sub_Lo)),
4406 Right_Opnd =>
4407 Make_Op_Ne (Loc,
4408 Left_Opnd => Duplicate_Subexpr (Aggr_Hi),
4409 Right_Opnd => Duplicate_Subexpr (Sub_Hi)));
4410 end if;
4412 if Present (Cond) then
4413 Insert_Action (N,
4414 Make_Raise_Constraint_Error (Loc,
4415 Condition => Cond,
4416 Reason => CE_Length_Check_Failed));
4417 end if;
4419 -- Now look inside the sub-aggregate to see if there is more work
4421 if Dim < Aggr_Dimension then
4423 -- Process positional components
4425 if Present (Expressions (Sub_Aggr)) then
4426 Expr := First (Expressions (Sub_Aggr));
4427 while Present (Expr) loop
4428 Check_Same_Aggr_Bounds (Expr, Dim + 1);
4429 Next (Expr);
4430 end loop;
4431 end if;
4433 -- Process component associations
4435 if Present (Component_Associations (Sub_Aggr)) then
4436 Assoc := First (Component_Associations (Sub_Aggr));
4437 while Present (Assoc) loop
4438 Expr := Expression (Assoc);
4439 Check_Same_Aggr_Bounds (Expr, Dim + 1);
4440 Next (Assoc);
4441 end loop;
4442 end if;
4443 end if;
4444 end Check_Same_Aggr_Bounds;
4446 ----------------------------
4447 -- Compute_Others_Present --
4448 ----------------------------
4450 procedure Compute_Others_Present (Sub_Aggr : Node_Id; Dim : Pos) is
4451 Assoc : Node_Id;
4452 Expr : Node_Id;
4454 begin
4455 if Present (Component_Associations (Sub_Aggr)) then
4456 Assoc := Last (Component_Associations (Sub_Aggr));
4458 if Nkind (First (Choices (Assoc))) = N_Others_Choice then
4459 Others_Present (Dim) := True;
4460 end if;
4461 end if;
4463 -- Now look inside the sub-aggregate to see if there is more work
4465 if Dim < Aggr_Dimension then
4467 -- Process positional components
4469 if Present (Expressions (Sub_Aggr)) then
4470 Expr := First (Expressions (Sub_Aggr));
4471 while Present (Expr) loop
4472 Compute_Others_Present (Expr, Dim + 1);
4473 Next (Expr);
4474 end loop;
4475 end if;
4477 -- Process component associations
4479 if Present (Component_Associations (Sub_Aggr)) then
4480 Assoc := First (Component_Associations (Sub_Aggr));
4481 while Present (Assoc) loop
4482 Expr := Expression (Assoc);
4483 Compute_Others_Present (Expr, Dim + 1);
4484 Next (Assoc);
4485 end loop;
4486 end if;
4487 end if;
4488 end Compute_Others_Present;
4490 ------------------------
4491 -- In_Place_Assign_OK --
4492 ------------------------
4494 function In_Place_Assign_OK return Boolean is
4495 Aggr_In : Node_Id;
4496 Aggr_Lo : Node_Id;
4497 Aggr_Hi : Node_Id;
4498 Obj_In : Node_Id;
4499 Obj_Lo : Node_Id;
4500 Obj_Hi : Node_Id;
4502 function Safe_Aggregate (Aggr : Node_Id) return Boolean;
4503 -- Check recursively that each component of a (sub)aggregate does
4504 -- not depend on the variable being assigned to.
4506 function Safe_Component (Expr : Node_Id) return Boolean;
4507 -- Verify that an expression cannot depend on the variable being
4508 -- assigned to. Room for improvement here (but less than before).
4510 --------------------
4511 -- Safe_Aggregate --
4512 --------------------
4514 function Safe_Aggregate (Aggr : Node_Id) return Boolean is
4515 Expr : Node_Id;
4517 begin
4518 if Present (Expressions (Aggr)) then
4519 Expr := First (Expressions (Aggr));
4520 while Present (Expr) loop
4521 if Nkind (Expr) = N_Aggregate then
4522 if not Safe_Aggregate (Expr) then
4523 return False;
4524 end if;
4526 elsif not Safe_Component (Expr) then
4527 return False;
4528 end if;
4530 Next (Expr);
4531 end loop;
4532 end if;
4534 if Present (Component_Associations (Aggr)) then
4535 Expr := First (Component_Associations (Aggr));
4536 while Present (Expr) loop
4537 if Nkind (Expression (Expr)) = N_Aggregate then
4538 if not Safe_Aggregate (Expression (Expr)) then
4539 return False;
4540 end if;
4542 -- If association has a box, no way to determine yet
4543 -- whether default can be assigned in place.
4545 elsif Box_Present (Expr) then
4546 return False;
4548 elsif not Safe_Component (Expression (Expr)) then
4549 return False;
4550 end if;
4552 Next (Expr);
4553 end loop;
4554 end if;
4556 return True;
4557 end Safe_Aggregate;
4559 --------------------
4560 -- Safe_Component --
4561 --------------------
4563 function Safe_Component (Expr : Node_Id) return Boolean is
4564 Comp : Node_Id := Expr;
4566 function Check_Component (Comp : Node_Id) return Boolean;
4567 -- Do the recursive traversal, after copy
4569 ---------------------
4570 -- Check_Component --
4571 ---------------------
4573 function Check_Component (Comp : Node_Id) return Boolean is
4574 begin
4575 if Is_Overloaded (Comp) then
4576 return False;
4577 end if;
4579 return Compile_Time_Known_Value (Comp)
4581 or else (Is_Entity_Name (Comp)
4582 and then Present (Entity (Comp))
4583 and then No (Renamed_Object (Entity (Comp))))
4585 or else (Nkind (Comp) = N_Attribute_Reference
4586 and then Check_Component (Prefix (Comp)))
4588 or else (Nkind (Comp) in N_Binary_Op
4589 and then Check_Component (Left_Opnd (Comp))
4590 and then Check_Component (Right_Opnd (Comp)))
4592 or else (Nkind (Comp) in N_Unary_Op
4593 and then Check_Component (Right_Opnd (Comp)))
4595 or else (Nkind (Comp) = N_Selected_Component
4596 and then Check_Component (Prefix (Comp)))
4598 or else (Nkind (Comp) = N_Unchecked_Type_Conversion
4599 and then Check_Component (Expression (Comp)));
4600 end Check_Component;
4602 -- Start of processing for Safe_Component
4604 begin
4605 -- If the component appears in an association that may correspond
4606 -- to more than one element, it is not analyzed before expansion
4607 -- into assignments, to avoid side effects. We analyze, but do not
4608 -- resolve the copy, to obtain sufficient entity information for
4609 -- the checks that follow. If component is overloaded we assume
4610 -- an unsafe function call.
4612 if not Analyzed (Comp) then
4613 if Is_Overloaded (Expr) then
4614 return False;
4616 elsif Nkind (Expr) = N_Aggregate
4617 and then not Is_Others_Aggregate (Expr)
4618 then
4619 return False;
4621 elsif Nkind (Expr) = N_Allocator then
4623 -- For now, too complex to analyze
4625 return False;
4626 end if;
4628 Comp := New_Copy_Tree (Expr);
4629 Set_Parent (Comp, Parent (Expr));
4630 Analyze (Comp);
4631 end if;
4633 if Nkind (Comp) = N_Aggregate then
4634 return Safe_Aggregate (Comp);
4635 else
4636 return Check_Component (Comp);
4637 end if;
4638 end Safe_Component;
4640 -- Start of processing for In_Place_Assign_OK
4642 begin
4643 if Present (Component_Associations (N)) then
4645 -- On assignment, sliding can take place, so we cannot do the
4646 -- assignment in place unless the bounds of the aggregate are
4647 -- statically equal to those of the target.
4649 -- If the aggregate is given by an others choice, the bounds are
4650 -- derived from the left-hand side, and the assignment is safe if
4651 -- the expression is.
4653 if Is_Others_Aggregate (N) then
4654 return
4655 Safe_Component
4656 (Expression (First (Component_Associations (N))));
4657 end if;
4659 Aggr_In := First_Index (Etype (N));
4661 if Nkind (Parent (N)) = N_Assignment_Statement then
4662 Obj_In := First_Index (Etype (Name (Parent (N))));
4664 else
4665 -- Context is an allocator. Check bounds of aggregate against
4666 -- given type in qualified expression.
4668 pragma Assert (Nkind (Parent (Parent (N))) = N_Allocator);
4669 Obj_In :=
4670 First_Index (Etype (Entity (Subtype_Mark (Parent (N)))));
4671 end if;
4673 while Present (Aggr_In) loop
4674 Get_Index_Bounds (Aggr_In, Aggr_Lo, Aggr_Hi);
4675 Get_Index_Bounds (Obj_In, Obj_Lo, Obj_Hi);
4677 if not Compile_Time_Known_Value (Aggr_Lo)
4678 or else not Compile_Time_Known_Value (Aggr_Hi)
4679 or else not Compile_Time_Known_Value (Obj_Lo)
4680 or else not Compile_Time_Known_Value (Obj_Hi)
4681 or else Expr_Value (Aggr_Lo) /= Expr_Value (Obj_Lo)
4682 or else Expr_Value (Aggr_Hi) /= Expr_Value (Obj_Hi)
4683 then
4684 return False;
4685 end if;
4687 Next_Index (Aggr_In);
4688 Next_Index (Obj_In);
4689 end loop;
4690 end if;
4692 -- Now check the component values themselves
4694 return Safe_Aggregate (N);
4695 end In_Place_Assign_OK;
4697 ------------------
4698 -- Others_Check --
4699 ------------------
4701 procedure Others_Check (Sub_Aggr : Node_Id; Dim : Pos) is
4702 Aggr_Lo : constant Node_Id := Aggr_Low (Dim);
4703 Aggr_Hi : constant Node_Id := Aggr_High (Dim);
4704 -- The bounds of the aggregate for this dimension
4706 Ind_Typ : constant Entity_Id := Aggr_Index_Typ (Dim);
4707 -- The index type for this dimension
4709 Need_To_Check : Boolean := False;
4711 Choices_Lo : Node_Id := Empty;
4712 Choices_Hi : Node_Id := Empty;
4713 -- The lowest and highest discrete choices for a named sub-aggregate
4715 Nb_Choices : Int := -1;
4716 -- The number of discrete non-others choices in this sub-aggregate
4718 Nb_Elements : Uint := Uint_0;
4719 -- The number of elements in a positional aggregate
4721 Cond : Node_Id := Empty;
4723 Assoc : Node_Id;
4724 Choice : Node_Id;
4725 Expr : Node_Id;
4727 begin
4728 -- Check if we have an others choice. If we do make sure that this
4729 -- sub-aggregate contains at least one element in addition to the
4730 -- others choice.
4732 if Range_Checks_Suppressed (Ind_Typ) then
4733 Need_To_Check := False;
4735 elsif Present (Expressions (Sub_Aggr))
4736 and then Present (Component_Associations (Sub_Aggr))
4737 then
4738 Need_To_Check := True;
4740 elsif Present (Component_Associations (Sub_Aggr)) then
4741 Assoc := Last (Component_Associations (Sub_Aggr));
4743 if Nkind (First (Choices (Assoc))) /= N_Others_Choice then
4744 Need_To_Check := False;
4746 else
4747 -- Count the number of discrete choices. Start with -1 because
4748 -- the others choice does not count.
4750 -- Is there some reason we do not use List_Length here ???
4752 Nb_Choices := -1;
4753 Assoc := First (Component_Associations (Sub_Aggr));
4754 while Present (Assoc) loop
4755 Choice := First (Choices (Assoc));
4756 while Present (Choice) loop
4757 Nb_Choices := Nb_Choices + 1;
4758 Next (Choice);
4759 end loop;
4761 Next (Assoc);
4762 end loop;
4764 -- If there is only an others choice nothing to do
4766 Need_To_Check := (Nb_Choices > 0);
4767 end if;
4769 else
4770 Need_To_Check := False;
4771 end if;
4773 -- If we are dealing with a positional sub-aggregate with an others
4774 -- choice then compute the number or positional elements.
4776 if Need_To_Check and then Present (Expressions (Sub_Aggr)) then
4777 Expr := First (Expressions (Sub_Aggr));
4778 Nb_Elements := Uint_0;
4779 while Present (Expr) loop
4780 Nb_Elements := Nb_Elements + 1;
4781 Next (Expr);
4782 end loop;
4784 -- If the aggregate contains discrete choices and an others choice
4785 -- compute the smallest and largest discrete choice values.
4787 elsif Need_To_Check then
4788 Compute_Choices_Lo_And_Choices_Hi : declare
4790 Table : Case_Table_Type (1 .. Nb_Choices);
4791 -- Used to sort all the different choice values
4793 J : Pos := 1;
4794 Low : Node_Id;
4795 High : Node_Id;
4797 begin
4798 Assoc := First (Component_Associations (Sub_Aggr));
4799 while Present (Assoc) loop
4800 Choice := First (Choices (Assoc));
4801 while Present (Choice) loop
4802 if Nkind (Choice) = N_Others_Choice then
4803 exit;
4804 end if;
4806 Get_Index_Bounds (Choice, Low, High);
4807 Table (J).Choice_Lo := Low;
4808 Table (J).Choice_Hi := High;
4810 J := J + 1;
4811 Next (Choice);
4812 end loop;
4814 Next (Assoc);
4815 end loop;
4817 -- Sort the discrete choices
4819 Sort_Case_Table (Table);
4821 Choices_Lo := Table (1).Choice_Lo;
4822 Choices_Hi := Table (Nb_Choices).Choice_Hi;
4823 end Compute_Choices_Lo_And_Choices_Hi;
4824 end if;
4826 -- If no others choice in this sub-aggregate, or the aggregate
4827 -- comprises only an others choice, nothing to do.
4829 if not Need_To_Check then
4830 Cond := Empty;
4832 -- If we are dealing with an aggregate containing an others choice
4833 -- and positional components, we generate the following test:
4835 -- if Ind_Typ'Pos (Aggr_Lo) + (Nb_Elements - 1) >
4836 -- Ind_Typ'Pos (Aggr_Hi)
4837 -- then
4838 -- raise Constraint_Error;
4839 -- end if;
4841 elsif Nb_Elements > Uint_0 then
4842 Cond :=
4843 Make_Op_Gt (Loc,
4844 Left_Opnd =>
4845 Make_Op_Add (Loc,
4846 Left_Opnd =>
4847 Make_Attribute_Reference (Loc,
4848 Prefix => New_Occurrence_Of (Ind_Typ, Loc),
4849 Attribute_Name => Name_Pos,
4850 Expressions =>
4851 New_List
4852 (Duplicate_Subexpr_Move_Checks (Aggr_Lo))),
4853 Right_Opnd => Make_Integer_Literal (Loc, Nb_Elements - 1)),
4855 Right_Opnd =>
4856 Make_Attribute_Reference (Loc,
4857 Prefix => New_Occurrence_Of (Ind_Typ, Loc),
4858 Attribute_Name => Name_Pos,
4859 Expressions => New_List (
4860 Duplicate_Subexpr_Move_Checks (Aggr_Hi))));
4862 -- If we are dealing with an aggregate containing an others choice
4863 -- and discrete choices we generate the following test:
4865 -- [constraint_error when
4866 -- Choices_Lo < Aggr_Lo or else Choices_Hi > Aggr_Hi];
4868 else
4869 Cond :=
4870 Make_Or_Else (Loc,
4871 Left_Opnd =>
4872 Make_Op_Lt (Loc,
4873 Left_Opnd => Duplicate_Subexpr_Move_Checks (Choices_Lo),
4874 Right_Opnd => Duplicate_Subexpr_Move_Checks (Aggr_Lo)),
4876 Right_Opnd =>
4877 Make_Op_Gt (Loc,
4878 Left_Opnd => Duplicate_Subexpr (Choices_Hi),
4879 Right_Opnd => Duplicate_Subexpr (Aggr_Hi)));
4880 end if;
4882 if Present (Cond) then
4883 Insert_Action (N,
4884 Make_Raise_Constraint_Error (Loc,
4885 Condition => Cond,
4886 Reason => CE_Length_Check_Failed));
4887 -- Questionable reason code, shouldn't that be a
4888 -- CE_Range_Check_Failed ???
4889 end if;
4891 -- Now look inside the sub-aggregate to see if there is more work
4893 if Dim < Aggr_Dimension then
4895 -- Process positional components
4897 if Present (Expressions (Sub_Aggr)) then
4898 Expr := First (Expressions (Sub_Aggr));
4899 while Present (Expr) loop
4900 Others_Check (Expr, Dim + 1);
4901 Next (Expr);
4902 end loop;
4903 end if;
4905 -- Process component associations
4907 if Present (Component_Associations (Sub_Aggr)) then
4908 Assoc := First (Component_Associations (Sub_Aggr));
4909 while Present (Assoc) loop
4910 Expr := Expression (Assoc);
4911 Others_Check (Expr, Dim + 1);
4912 Next (Assoc);
4913 end loop;
4914 end if;
4915 end if;
4916 end Others_Check;
4918 -------------------------
4919 -- Safe_Left_Hand_Side --
4920 -------------------------
4922 function Safe_Left_Hand_Side (N : Node_Id) return Boolean is
4923 function Is_Safe_Index (Indx : Node_Id) return Boolean;
4924 -- If the left-hand side includes an indexed component, check that
4925 -- the indexes are free of side-effect.
4927 -------------------
4928 -- Is_Safe_Index --
4929 -------------------
4931 function Is_Safe_Index (Indx : Node_Id) return Boolean is
4932 begin
4933 if Is_Entity_Name (Indx) then
4934 return True;
4936 elsif Nkind (Indx) = N_Integer_Literal then
4937 return True;
4939 elsif Nkind (Indx) = N_Function_Call
4940 and then Is_Entity_Name (Name (Indx))
4941 and then Has_Pragma_Pure_Function (Entity (Name (Indx)))
4942 then
4943 return True;
4945 elsif Nkind (Indx) = N_Type_Conversion
4946 and then Is_Safe_Index (Expression (Indx))
4947 then
4948 return True;
4950 else
4951 return False;
4952 end if;
4953 end Is_Safe_Index;
4955 -- Start of processing for Safe_Left_Hand_Side
4957 begin
4958 if Is_Entity_Name (N) then
4959 return True;
4961 elsif Nkind_In (N, N_Explicit_Dereference, N_Selected_Component)
4962 and then Safe_Left_Hand_Side (Prefix (N))
4963 then
4964 return True;
4966 elsif Nkind (N) = N_Indexed_Component
4967 and then Safe_Left_Hand_Side (Prefix (N))
4968 and then Is_Safe_Index (First (Expressions (N)))
4969 then
4970 return True;
4972 elsif Nkind (N) = N_Unchecked_Type_Conversion then
4973 return Safe_Left_Hand_Side (Expression (N));
4975 else
4976 return False;
4977 end if;
4978 end Safe_Left_Hand_Side;
4980 -- Local variables
4982 Tmp : Entity_Id;
4983 -- Holds the temporary aggregate value
4985 Tmp_Decl : Node_Id;
4986 -- Holds the declaration of Tmp
4988 Aggr_Code : List_Id;
4989 Parent_Node : Node_Id;
4990 Parent_Kind : Node_Kind;
4992 -- Start of processing for Expand_Array_Aggregate
4994 begin
4995 -- Do not touch the special aggregates of attributes used for Asm calls
4997 if Is_RTE (Ctyp, RE_Asm_Input_Operand)
4998 or else Is_RTE (Ctyp, RE_Asm_Output_Operand)
4999 then
5000 return;
5002 -- Do not expand an aggregate for an array type which contains tasks if
5003 -- the aggregate is associated with an unexpanded return statement of a
5004 -- build-in-place function. The aggregate is expanded when the related
5005 -- return statement (rewritten into an extended return) is processed.
5006 -- This delay ensures that any temporaries and initialization code
5007 -- generated for the aggregate appear in the proper return block and
5008 -- use the correct _chain and _master.
5010 elsif Has_Task (Base_Type (Etype (N)))
5011 and then Nkind (Parent (N)) = N_Simple_Return_Statement
5012 and then Is_Build_In_Place_Function
5013 (Return_Applies_To (Return_Statement_Entity (Parent (N))))
5014 then
5015 return;
5017 -- Do not attempt expansion if error already detected. We may reach this
5018 -- point in spite of previous errors when compiling with -gnatq, to
5019 -- force all possible errors (this is the usual ACATS mode).
5021 elsif Error_Posted (N) then
5022 return;
5023 end if;
5025 -- If the semantic analyzer has determined that aggregate N will raise
5026 -- Constraint_Error at run time, then the aggregate node has been
5027 -- replaced with an N_Raise_Constraint_Error node and we should
5028 -- never get here.
5030 pragma Assert (not Raises_Constraint_Error (N));
5032 -- STEP 1a
5034 -- Check that the index range defined by aggregate bounds is
5035 -- compatible with corresponding index subtype.
5037 Index_Compatibility_Check : declare
5038 Aggr_Index_Range : Node_Id := First_Index (Typ);
5039 -- The current aggregate index range
5041 Index_Constraint : Node_Id := First_Index (Etype (Typ));
5042 -- The corresponding index constraint against which we have to
5043 -- check the above aggregate index range.
5045 begin
5046 Compute_Others_Present (N, 1);
5048 for J in 1 .. Aggr_Dimension loop
5049 -- There is no need to emit a check if an others choice is present
5050 -- for this array aggregate dimension since in this case one of
5051 -- N's sub-aggregates has taken its bounds from the context and
5052 -- these bounds must have been checked already. In addition all
5053 -- sub-aggregates corresponding to the same dimension must all
5054 -- have the same bounds (checked in (c) below).
5056 if not Range_Checks_Suppressed (Etype (Index_Constraint))
5057 and then not Others_Present (J)
5058 then
5059 -- We don't use Checks.Apply_Range_Check here because it emits
5060 -- a spurious check. Namely it checks that the range defined by
5061 -- the aggregate bounds is non empty. But we know this already
5062 -- if we get here.
5064 Check_Bounds (Aggr_Index_Range, Index_Constraint);
5065 end if;
5067 -- Save the low and high bounds of the aggregate index as well as
5068 -- the index type for later use in checks (b) and (c) below.
5070 Aggr_Low (J) := Low_Bound (Aggr_Index_Range);
5071 Aggr_High (J) := High_Bound (Aggr_Index_Range);
5073 Aggr_Index_Typ (J) := Etype (Index_Constraint);
5075 Next_Index (Aggr_Index_Range);
5076 Next_Index (Index_Constraint);
5077 end loop;
5078 end Index_Compatibility_Check;
5080 -- STEP 1b
5082 -- If an others choice is present check that no aggregate index is
5083 -- outside the bounds of the index constraint.
5085 Others_Check (N, 1);
5087 -- STEP 1c
5089 -- For multidimensional arrays make sure that all subaggregates
5090 -- corresponding to the same dimension have the same bounds.
5092 if Aggr_Dimension > 1 then
5093 Check_Same_Aggr_Bounds (N, 1);
5094 end if;
5096 -- STEP 1d
5098 -- If we have a default component value, or simple initialization is
5099 -- required for the component type, then we replace <> in component
5100 -- associations by the required default value.
5102 declare
5103 Default_Val : Node_Id;
5104 Assoc : Node_Id;
5106 begin
5107 if (Present (Default_Aspect_Component_Value (Typ))
5108 or else Needs_Simple_Initialization (Ctyp))
5109 and then Present (Component_Associations (N))
5110 then
5111 Assoc := First (Component_Associations (N));
5112 while Present (Assoc) loop
5113 if Nkind (Assoc) = N_Component_Association
5114 and then Box_Present (Assoc)
5115 then
5116 Set_Box_Present (Assoc, False);
5118 if Present (Default_Aspect_Component_Value (Typ)) then
5119 Default_Val := Default_Aspect_Component_Value (Typ);
5120 else
5121 Default_Val := Get_Simple_Init_Val (Ctyp, N);
5122 end if;
5124 Set_Expression (Assoc, New_Copy_Tree (Default_Val));
5125 Analyze_And_Resolve (Expression (Assoc), Ctyp);
5126 end if;
5128 Next (Assoc);
5129 end loop;
5130 end if;
5131 end;
5133 -- STEP 2
5135 -- Here we test for is packed array aggregate that we can handle at
5136 -- compile time. If so, return with transformation done. Note that we do
5137 -- this even if the aggregate is nested, because once we have done this
5138 -- processing, there is no more nested aggregate.
5140 if Packed_Array_Aggregate_Handled (N) then
5141 return;
5142 end if;
5144 -- At this point we try to convert to positional form
5146 if Ekind (Current_Scope) = E_Package
5147 and then Static_Elaboration_Desired (Current_Scope)
5148 then
5149 Convert_To_Positional (N, Max_Others_Replicate => 100);
5150 else
5151 Convert_To_Positional (N);
5152 end if;
5154 -- if the result is no longer an aggregate (e.g. it may be a string
5155 -- literal, or a temporary which has the needed value), then we are
5156 -- done, since there is no longer a nested aggregate.
5158 if Nkind (N) /= N_Aggregate then
5159 return;
5161 -- We are also done if the result is an analyzed aggregate, indicating
5162 -- that Convert_To_Positional succeeded and reanalyzed the rewritten
5163 -- aggregate.
5165 elsif Analyzed (N) and then N /= Original_Node (N) then
5166 return;
5167 end if;
5169 -- If all aggregate components are compile-time known and the aggregate
5170 -- has been flattened, nothing left to do. The same occurs if the
5171 -- aggregate is used to initialize the components of a statically
5172 -- allocated dispatch table.
5174 if Compile_Time_Known_Aggregate (N)
5175 or else Is_Static_Dispatch_Table_Aggregate (N)
5176 then
5177 Set_Expansion_Delayed (N, False);
5178 return;
5179 end if;
5181 -- Now see if back end processing is possible
5183 if Backend_Processing_Possible (N) then
5185 -- If the aggregate is static but the constraints are not, build
5186 -- a static subtype for the aggregate, so that Gigi can place it
5187 -- in static memory. Perform an unchecked_conversion to the non-
5188 -- static type imposed by the context.
5190 declare
5191 Itype : constant Entity_Id := Etype (N);
5192 Index : Node_Id;
5193 Needs_Type : Boolean := False;
5195 begin
5196 Index := First_Index (Itype);
5197 while Present (Index) loop
5198 if not Is_OK_Static_Subtype (Etype (Index)) then
5199 Needs_Type := True;
5200 exit;
5201 else
5202 Next_Index (Index);
5203 end if;
5204 end loop;
5206 if Needs_Type then
5207 Build_Constrained_Type (Positional => True);
5208 Rewrite (N, Unchecked_Convert_To (Itype, N));
5209 Analyze (N);
5210 end if;
5211 end;
5213 return;
5214 end if;
5216 -- STEP 3
5218 -- Delay expansion for nested aggregates: it will be taken care of
5219 -- when the parent aggregate is expanded.
5221 Parent_Node := Parent (N);
5222 Parent_Kind := Nkind (Parent_Node);
5224 if Parent_Kind = N_Qualified_Expression then
5225 Parent_Node := Parent (Parent_Node);
5226 Parent_Kind := Nkind (Parent_Node);
5227 end if;
5229 if Parent_Kind = N_Aggregate
5230 or else Parent_Kind = N_Extension_Aggregate
5231 or else Parent_Kind = N_Component_Association
5232 or else (Parent_Kind = N_Object_Declaration
5233 and then Needs_Finalization (Typ))
5234 or else (Parent_Kind = N_Assignment_Statement
5235 and then Inside_Init_Proc)
5236 then
5237 if Static_Array_Aggregate (N)
5238 or else Compile_Time_Known_Aggregate (N)
5239 then
5240 Set_Expansion_Delayed (N, False);
5241 return;
5242 else
5243 Set_Expansion_Delayed (N);
5244 return;
5245 end if;
5246 end if;
5248 -- STEP 4
5250 -- Look if in place aggregate expansion is possible
5252 -- For object declarations we build the aggregate in place, unless
5253 -- the array is bit-packed or the component is controlled.
5255 -- For assignments we do the assignment in place if all the component
5256 -- associations have compile-time known values. For other cases we
5257 -- create a temporary. The analysis for safety of on-line assignment
5258 -- is delicate, i.e. we don't know how to do it fully yet ???
5260 -- For allocators we assign to the designated object in place if the
5261 -- aggregate meets the same conditions as other in-place assignments.
5262 -- In this case the aggregate may not come from source but was created
5263 -- for default initialization, e.g. with Initialize_Scalars.
5265 if Requires_Transient_Scope (Typ) then
5266 Establish_Transient_Scope
5267 (N, Sec_Stack => Has_Controlled_Component (Typ));
5268 end if;
5270 if Has_Default_Init_Comps (N) then
5271 Maybe_In_Place_OK := False;
5273 elsif Is_Bit_Packed_Array (Typ)
5274 or else Has_Controlled_Component (Typ)
5275 then
5276 Maybe_In_Place_OK := False;
5278 else
5279 Maybe_In_Place_OK :=
5280 (Nkind (Parent (N)) = N_Assignment_Statement
5281 and then In_Place_Assign_OK)
5283 or else
5284 (Nkind (Parent (Parent (N))) = N_Allocator
5285 and then In_Place_Assign_OK);
5286 end if;
5288 -- If this is an array of tasks, it will be expanded into build-in-place
5289 -- assignments. Build an activation chain for the tasks now.
5291 if Has_Task (Etype (N)) then
5292 Build_Activation_Chain_Entity (N);
5293 end if;
5295 -- Perform in-place expansion of aggregate in an object declaration.
5296 -- Note: actions generated for the aggregate will be captured in an
5297 -- expression-with-actions statement so that they can be transferred
5298 -- to freeze actions later if there is an address clause for the
5299 -- object. (Note: we don't use a block statement because this would
5300 -- cause generated freeze nodes to be elaborated in the wrong scope).
5302 -- Should document these individual tests ???
5304 if not Has_Default_Init_Comps (N)
5305 and then Comes_From_Source (Parent_Node)
5306 and then Parent_Kind = N_Object_Declaration
5307 and then not
5308 Must_Slide (Etype (Defining_Identifier (Parent_Node)), Typ)
5309 and then N = Expression (Parent_Node)
5310 and then not Is_Bit_Packed_Array (Typ)
5311 and then not Has_Controlled_Component (Typ)
5312 then
5313 In_Place_Assign_OK_For_Declaration := True;
5314 Tmp := Defining_Identifier (Parent (N));
5315 Set_No_Initialization (Parent (N));
5316 Set_Expression (Parent (N), Empty);
5318 -- Set kind and type of the entity, for use in the analysis
5319 -- of the subsequent assignments. If the nominal type is not
5320 -- constrained, build a subtype from the known bounds of the
5321 -- aggregate. If the declaration has a subtype mark, use it,
5322 -- otherwise use the itype of the aggregate.
5324 Set_Ekind (Tmp, E_Variable);
5326 if not Is_Constrained (Typ) then
5327 Build_Constrained_Type (Positional => False);
5329 elsif Is_Entity_Name (Object_Definition (Parent (N)))
5330 and then Is_Constrained (Entity (Object_Definition (Parent (N))))
5331 then
5332 Set_Etype (Tmp, Entity (Object_Definition (Parent (N))));
5334 else
5335 Set_Size_Known_At_Compile_Time (Typ, False);
5336 Set_Etype (Tmp, Typ);
5337 end if;
5339 elsif Maybe_In_Place_OK
5340 and then Nkind (Parent (N)) = N_Qualified_Expression
5341 and then Nkind (Parent (Parent (N))) = N_Allocator
5342 then
5343 Set_Expansion_Delayed (N);
5344 return;
5346 -- In the remaining cases the aggregate is the RHS of an assignment
5348 elsif Maybe_In_Place_OK
5349 and then Safe_Left_Hand_Side (Name (Parent (N)))
5350 then
5351 Tmp := Name (Parent (N));
5353 if Etype (Tmp) /= Etype (N) then
5354 Apply_Length_Check (N, Etype (Tmp));
5356 if Nkind (N) = N_Raise_Constraint_Error then
5358 -- Static error, nothing further to expand
5360 return;
5361 end if;
5362 end if;
5364 -- If a slice assignment has an aggregate with a single others_choice,
5365 -- the assignment can be done in place even if bounds are not static,
5366 -- by converting it into a loop over the discrete range of the slice.
5368 elsif Maybe_In_Place_OK
5369 and then Nkind (Name (Parent (N))) = N_Slice
5370 and then Is_Others_Aggregate (N)
5371 then
5372 Tmp := Name (Parent (N));
5374 -- Set type of aggregate to be type of lhs in assignment, in order
5375 -- to suppress redundant length checks.
5377 Set_Etype (N, Etype (Tmp));
5379 -- Step 5
5381 -- In place aggregate expansion is not possible
5383 else
5384 Maybe_In_Place_OK := False;
5385 Tmp := Make_Temporary (Loc, 'A', N);
5386 Tmp_Decl :=
5387 Make_Object_Declaration (Loc,
5388 Defining_Identifier => Tmp,
5389 Object_Definition => New_Occurrence_Of (Typ, Loc));
5390 Set_No_Initialization (Tmp_Decl, True);
5392 -- If we are within a loop, the temporary will be pushed on the
5393 -- stack at each iteration. If the aggregate is the expression for an
5394 -- allocator, it will be immediately copied to the heap and can
5395 -- be reclaimed at once. We create a transient scope around the
5396 -- aggregate for this purpose.
5398 if Ekind (Current_Scope) = E_Loop
5399 and then Nkind (Parent (Parent (N))) = N_Allocator
5400 then
5401 Establish_Transient_Scope (N, False);
5402 end if;
5404 Insert_Action (N, Tmp_Decl);
5405 end if;
5407 -- Construct and insert the aggregate code. We can safely suppress index
5408 -- checks because this code is guaranteed not to raise CE on index
5409 -- checks. However we should *not* suppress all checks.
5411 declare
5412 Target : Node_Id;
5414 begin
5415 if Nkind (Tmp) = N_Defining_Identifier then
5416 Target := New_Occurrence_Of (Tmp, Loc);
5418 else
5419 if Has_Default_Init_Comps (N) then
5421 -- Ada 2005 (AI-287): This case has not been analyzed???
5423 raise Program_Error;
5424 end if;
5426 -- Name in assignment is explicit dereference
5428 Target := New_Copy (Tmp);
5429 end if;
5431 -- If we are to generate an in place assignment for a declaration or
5432 -- an assignment statement, and the assignment can be done directly
5433 -- by the back end, then do not expand further.
5435 -- ??? We can also do that if in place expansion is not possible but
5436 -- then we could go into an infinite recursion.
5438 if (In_Place_Assign_OK_For_Declaration or else Maybe_In_Place_OK)
5439 and then VM_Target = No_VM
5440 and then not AAMP_On_Target
5441 and then not Generate_SCIL
5442 and then not Possible_Bit_Aligned_Component (Target)
5443 and then not Is_Possibly_Unaligned_Slice (Target)
5444 and then Aggr_Assignment_OK_For_Backend (N)
5445 then
5446 if Maybe_In_Place_OK then
5447 return;
5448 end if;
5450 Aggr_Code :=
5451 New_List (
5452 Make_Assignment_Statement (Loc,
5453 Name => Target,
5454 Expression => New_Copy (N)));
5456 else
5457 Aggr_Code :=
5458 Build_Array_Aggr_Code (N,
5459 Ctype => Ctyp,
5460 Index => First_Index (Typ),
5461 Into => Target,
5462 Scalar_Comp => Is_Scalar_Type (Ctyp));
5463 end if;
5465 -- Save the last assignment statement associated with the aggregate
5466 -- when building a controlled object. This reference is utilized by
5467 -- the finalization machinery when marking an object as successfully
5468 -- initialized.
5470 if Needs_Finalization (Typ)
5471 and then Is_Entity_Name (Target)
5472 and then Present (Entity (Target))
5473 and then Ekind_In (Entity (Target), E_Constant, E_Variable)
5474 then
5475 Set_Last_Aggregate_Assignment (Entity (Target), Last (Aggr_Code));
5476 end if;
5477 end;
5479 -- If the aggregate is the expression in a declaration, the expanded
5480 -- code must be inserted after it. The defining entity might not come
5481 -- from source if this is part of an inlined body, but the declaration
5482 -- itself will.
5484 if Comes_From_Source (Tmp)
5485 or else
5486 (Nkind (Parent (N)) = N_Object_Declaration
5487 and then Comes_From_Source (Parent (N))
5488 and then Tmp = Defining_Entity (Parent (N)))
5489 then
5490 declare
5491 Node_After : constant Node_Id := Next (Parent_Node);
5493 begin
5494 Insert_Actions_After (Parent_Node, Aggr_Code);
5496 if Parent_Kind = N_Object_Declaration then
5497 Collect_Initialization_Statements
5498 (Obj => Tmp, N => Parent_Node, Node_After => Node_After);
5499 end if;
5500 end;
5502 else
5503 Insert_Actions (N, Aggr_Code);
5504 end if;
5506 -- If the aggregate has been assigned in place, remove the original
5507 -- assignment.
5509 if Nkind (Parent (N)) = N_Assignment_Statement
5510 and then Maybe_In_Place_OK
5511 then
5512 Rewrite (Parent (N), Make_Null_Statement (Loc));
5514 elsif Nkind (Parent (N)) /= N_Object_Declaration
5515 or else Tmp /= Defining_Identifier (Parent (N))
5516 then
5517 Rewrite (N, New_Occurrence_Of (Tmp, Loc));
5518 Analyze_And_Resolve (N, Typ);
5519 end if;
5520 end Expand_Array_Aggregate;
5522 ------------------------
5523 -- Expand_N_Aggregate --
5524 ------------------------
5526 procedure Expand_N_Aggregate (N : Node_Id) is
5527 begin
5528 -- Record aggregate case
5530 if Is_Record_Type (Etype (N)) then
5531 Expand_Record_Aggregate (N);
5533 -- Array aggregate case
5535 else
5536 -- A special case, if we have a string subtype with bounds 1 .. N,
5537 -- where N is known at compile time, and the aggregate is of the
5538 -- form (others => 'x'), with a single choice and no expressions,
5539 -- and N is less than 80 (an arbitrary limit for now), then replace
5540 -- the aggregate by the equivalent string literal (but do not mark
5541 -- it as static since it is not).
5543 -- Note: this entire circuit is redundant with respect to code in
5544 -- Expand_Array_Aggregate that collapses others choices to positional
5545 -- form, but there are two problems with that circuit:
5547 -- a) It is limited to very small cases due to ill-understood
5548 -- interactions with bootstrapping. That limit is removed by
5549 -- use of the No_Implicit_Loops restriction.
5551 -- b) It incorrectly ends up with the resulting expressions being
5552 -- considered static when they are not. For example, the
5553 -- following test should fail:
5555 -- pragma Restrictions (No_Implicit_Loops);
5556 -- package NonSOthers4 is
5557 -- B : constant String (1 .. 6) := (others => 'A');
5558 -- DH : constant String (1 .. 8) := B & "BB";
5559 -- X : Integer;
5560 -- pragma Export (C, X, Link_Name => DH);
5561 -- end;
5563 -- But it succeeds (DH looks static to pragma Export)
5565 -- To be sorted out ???
5567 if Present (Component_Associations (N)) then
5568 declare
5569 CA : constant Node_Id := First (Component_Associations (N));
5570 MX : constant := 80;
5572 begin
5573 if Nkind (First (Choices (CA))) = N_Others_Choice
5574 and then Nkind (Expression (CA)) = N_Character_Literal
5575 and then No (Expressions (N))
5576 then
5577 declare
5578 T : constant Entity_Id := Etype (N);
5579 X : constant Node_Id := First_Index (T);
5580 EC : constant Node_Id := Expression (CA);
5581 CV : constant Uint := Char_Literal_Value (EC);
5582 CC : constant Int := UI_To_Int (CV);
5584 begin
5585 if Nkind (X) = N_Range
5586 and then Compile_Time_Known_Value (Low_Bound (X))
5587 and then Expr_Value (Low_Bound (X)) = 1
5588 and then Compile_Time_Known_Value (High_Bound (X))
5589 then
5590 declare
5591 Hi : constant Uint := Expr_Value (High_Bound (X));
5593 begin
5594 if Hi <= MX then
5595 Start_String;
5597 for J in 1 .. UI_To_Int (Hi) loop
5598 Store_String_Char (Char_Code (CC));
5599 end loop;
5601 Rewrite (N,
5602 Make_String_Literal (Sloc (N),
5603 Strval => End_String));
5605 if CC >= Int (2 ** 16) then
5606 Set_Has_Wide_Wide_Character (N);
5607 elsif CC >= Int (2 ** 8) then
5608 Set_Has_Wide_Character (N);
5609 end if;
5611 Analyze_And_Resolve (N, T);
5612 Set_Is_Static_Expression (N, False);
5613 return;
5614 end if;
5615 end;
5616 end if;
5617 end;
5618 end if;
5619 end;
5620 end if;
5622 -- Not that special case, so normal expansion of array aggregate
5624 Expand_Array_Aggregate (N);
5625 end if;
5627 exception
5628 when RE_Not_Available =>
5629 return;
5630 end Expand_N_Aggregate;
5632 ----------------------------------
5633 -- Expand_N_Extension_Aggregate --
5634 ----------------------------------
5636 -- If the ancestor part is an expression, add a component association for
5637 -- the parent field. If the type of the ancestor part is not the direct
5638 -- parent of the expected type, build recursively the needed ancestors.
5639 -- If the ancestor part is a subtype_mark, replace aggregate with a decla-
5640 -- ration for a temporary of the expected type, followed by individual
5641 -- assignments to the given components.
5643 procedure Expand_N_Extension_Aggregate (N : Node_Id) is
5644 Loc : constant Source_Ptr := Sloc (N);
5645 A : constant Node_Id := Ancestor_Part (N);
5646 Typ : constant Entity_Id := Etype (N);
5648 begin
5649 -- If the ancestor is a subtype mark, an init proc must be called
5650 -- on the resulting object which thus has to be materialized in
5651 -- the front-end
5653 if Is_Entity_Name (A) and then Is_Type (Entity (A)) then
5654 Convert_To_Assignments (N, Typ);
5656 -- The extension aggregate is transformed into a record aggregate
5657 -- of the following form (c1 and c2 are inherited components)
5659 -- (Exp with c3 => a, c4 => b)
5660 -- ==> (c1 => Exp.c1, c2 => Exp.c2, c3 => a, c4 => b)
5662 else
5663 Set_Etype (N, Typ);
5665 if Tagged_Type_Expansion then
5666 Expand_Record_Aggregate (N,
5667 Orig_Tag =>
5668 New_Occurrence_Of
5669 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc),
5670 Parent_Expr => A);
5672 -- No tag is needed in the case of a VM
5674 else
5675 Expand_Record_Aggregate (N, Parent_Expr => A);
5676 end if;
5677 end if;
5679 exception
5680 when RE_Not_Available =>
5681 return;
5682 end Expand_N_Extension_Aggregate;
5684 -----------------------------
5685 -- Expand_Record_Aggregate --
5686 -----------------------------
5688 procedure Expand_Record_Aggregate
5689 (N : Node_Id;
5690 Orig_Tag : Node_Id := Empty;
5691 Parent_Expr : Node_Id := Empty)
5693 Loc : constant Source_Ptr := Sloc (N);
5694 Comps : constant List_Id := Component_Associations (N);
5695 Typ : constant Entity_Id := Etype (N);
5696 Base_Typ : constant Entity_Id := Base_Type (Typ);
5698 Static_Components : Boolean := True;
5699 -- Flag to indicate whether all components are compile-time known,
5700 -- and the aggregate can be constructed statically and handled by
5701 -- the back-end.
5703 function Compile_Time_Known_Composite_Value (N : Node_Id) return Boolean;
5704 -- Returns true if N is an expression of composite type which can be
5705 -- fully evaluated at compile time without raising constraint error.
5706 -- Such expressions can be passed as is to Gigi without any expansion.
5708 -- This returns true for N_Aggregate with Compile_Time_Known_Aggregate
5709 -- set and constants whose expression is such an aggregate, recursively.
5711 function Component_Not_OK_For_Backend return Boolean;
5712 -- Check for presence of a component which makes it impossible for the
5713 -- backend to process the aggregate, thus requiring the use of a series
5714 -- of assignment statements. Cases checked for are a nested aggregate
5715 -- needing Late_Expansion, the presence of a tagged component which may
5716 -- need tag adjustment, and a bit unaligned component reference.
5718 -- We also force expansion into assignments if a component is of a
5719 -- mutable type (including a private type with discriminants) because
5720 -- in that case the size of the component to be copied may be smaller
5721 -- than the side of the target, and there is no simple way for gigi
5722 -- to compute the size of the object to be copied.
5724 -- NOTE: This is part of the ongoing work to define precisely the
5725 -- interface between front-end and back-end handling of aggregates.
5726 -- In general it is desirable to pass aggregates as they are to gigi,
5727 -- in order to minimize elaboration code. This is one case where the
5728 -- semantics of Ada complicate the analysis and lead to anomalies in
5729 -- the gcc back-end if the aggregate is not expanded into assignments.
5731 function Has_Visible_Private_Ancestor (Id : E) return Boolean;
5732 -- If any ancestor of the current type is private, the aggregate
5733 -- cannot be built in place. We cannot rely on Has_Private_Ancestor,
5734 -- because it will not be set when type and its parent are in the
5735 -- same scope, and the parent component needs expansion.
5737 function Top_Level_Aggregate (N : Node_Id) return Node_Id;
5738 -- For nested aggregates return the ultimate enclosing aggregate; for
5739 -- non-nested aggregates return N.
5741 ----------------------------------------
5742 -- Compile_Time_Known_Composite_Value --
5743 ----------------------------------------
5745 function Compile_Time_Known_Composite_Value
5746 (N : Node_Id) return Boolean
5748 begin
5749 -- If we have an entity name, then see if it is the name of a
5750 -- constant and if so, test the corresponding constant value.
5752 if Is_Entity_Name (N) then
5753 declare
5754 E : constant Entity_Id := Entity (N);
5755 V : Node_Id;
5756 begin
5757 if Ekind (E) /= E_Constant then
5758 return False;
5759 else
5760 V := Constant_Value (E);
5761 return Present (V)
5762 and then Compile_Time_Known_Composite_Value (V);
5763 end if;
5764 end;
5766 -- We have a value, see if it is compile time known
5768 else
5769 if Nkind (N) = N_Aggregate then
5770 return Compile_Time_Known_Aggregate (N);
5771 end if;
5773 -- All other types of values are not known at compile time
5775 return False;
5776 end if;
5778 end Compile_Time_Known_Composite_Value;
5780 ----------------------------------
5781 -- Component_Not_OK_For_Backend --
5782 ----------------------------------
5784 function Component_Not_OK_For_Backend return Boolean is
5785 C : Node_Id;
5786 Expr_Q : Node_Id;
5788 begin
5789 if No (Comps) then
5790 return False;
5791 end if;
5793 C := First (Comps);
5794 while Present (C) loop
5796 -- If the component has box initialization, expansion is needed
5797 -- and component is not ready for backend.
5799 if Box_Present (C) then
5800 return True;
5801 end if;
5803 if Nkind (Expression (C)) = N_Qualified_Expression then
5804 Expr_Q := Expression (Expression (C));
5805 else
5806 Expr_Q := Expression (C);
5807 end if;
5809 -- Return true if the aggregate has any associations for tagged
5810 -- components that may require tag adjustment.
5812 -- These are cases where the source expression may have a tag that
5813 -- could differ from the component tag (e.g., can occur for type
5814 -- conversions and formal parameters). (Tag adjustment not needed
5815 -- if VM_Target because object tags are implicit in the machine.)
5817 if Is_Tagged_Type (Etype (Expr_Q))
5818 and then (Nkind (Expr_Q) = N_Type_Conversion
5819 or else (Is_Entity_Name (Expr_Q)
5820 and then
5821 Ekind (Entity (Expr_Q)) in Formal_Kind))
5822 and then Tagged_Type_Expansion
5823 then
5824 Static_Components := False;
5825 return True;
5827 elsif Is_Delayed_Aggregate (Expr_Q) then
5828 Static_Components := False;
5829 return True;
5831 elsif Possible_Bit_Aligned_Component (Expr_Q) then
5832 Static_Components := False;
5833 return True;
5834 end if;
5836 if Is_Elementary_Type (Etype (Expr_Q)) then
5837 if not Compile_Time_Known_Value (Expr_Q) then
5838 Static_Components := False;
5839 end if;
5841 elsif not Compile_Time_Known_Composite_Value (Expr_Q) then
5842 Static_Components := False;
5844 if Is_Private_Type (Etype (Expr_Q))
5845 and then Has_Discriminants (Etype (Expr_Q))
5846 then
5847 return True;
5848 end if;
5849 end if;
5851 Next (C);
5852 end loop;
5854 return False;
5855 end Component_Not_OK_For_Backend;
5857 -----------------------------------
5858 -- Has_Visible_Private_Ancestor --
5859 -----------------------------------
5861 function Has_Visible_Private_Ancestor (Id : E) return Boolean is
5862 R : constant Entity_Id := Root_Type (Id);
5863 T1 : Entity_Id := Id;
5865 begin
5866 loop
5867 if Is_Private_Type (T1) then
5868 return True;
5870 elsif T1 = R then
5871 return False;
5873 else
5874 T1 := Etype (T1);
5875 end if;
5876 end loop;
5877 end Has_Visible_Private_Ancestor;
5879 -------------------------
5880 -- Top_Level_Aggregate --
5881 -------------------------
5883 function Top_Level_Aggregate (N : Node_Id) return Node_Id is
5884 Aggr : Node_Id;
5886 begin
5887 Aggr := N;
5888 while Present (Parent (Aggr))
5889 and then Nkind_In (Parent (Aggr), N_Component_Association,
5890 N_Aggregate)
5891 loop
5892 Aggr := Parent (Aggr);
5893 end loop;
5895 return Aggr;
5896 end Top_Level_Aggregate;
5898 -- Local variables
5900 Top_Level_Aggr : constant Node_Id := Top_Level_Aggregate (N);
5901 Tag_Value : Node_Id;
5902 Comp : Entity_Id;
5903 New_Comp : Node_Id;
5905 -- Start of processing for Expand_Record_Aggregate
5907 begin
5908 -- If the aggregate is to be assigned to an atomic variable, we have
5909 -- to prevent a piecemeal assignment even if the aggregate is to be
5910 -- expanded. We create a temporary for the aggregate, and assign the
5911 -- temporary instead, so that the back end can generate an atomic move
5912 -- for it.
5914 if Is_Atomic (Typ)
5915 and then Comes_From_Source (Parent (N))
5916 and then Is_Atomic_Aggregate (N, Typ)
5917 then
5918 return;
5920 -- No special management required for aggregates used to initialize
5921 -- statically allocated dispatch tables
5923 elsif Is_Static_Dispatch_Table_Aggregate (N) then
5924 return;
5925 end if;
5927 -- Ada 2005 (AI-318-2): We need to convert to assignments if components
5928 -- are build-in-place function calls. The assignments will each turn
5929 -- into a build-in-place function call. If components are all static,
5930 -- we can pass the aggregate to the backend regardless of limitedness.
5932 -- Extension aggregates, aggregates in extended return statements, and
5933 -- aggregates for C++ imported types must be expanded.
5935 if Ada_Version >= Ada_2005 and then Is_Limited_View (Typ) then
5936 if not Nkind_In (Parent (N), N_Object_Declaration,
5937 N_Component_Association)
5938 then
5939 Convert_To_Assignments (N, Typ);
5941 elsif Nkind (N) = N_Extension_Aggregate
5942 or else Convention (Typ) = Convention_CPP
5943 then
5944 Convert_To_Assignments (N, Typ);
5946 elsif not Size_Known_At_Compile_Time (Typ)
5947 or else Component_Not_OK_For_Backend
5948 or else not Static_Components
5949 then
5950 Convert_To_Assignments (N, Typ);
5952 else
5953 Set_Compile_Time_Known_Aggregate (N);
5954 Set_Expansion_Delayed (N, False);
5955 end if;
5957 -- Gigi doesn't properly handle temporaries of variable size so we
5958 -- generate it in the front-end
5960 elsif not Size_Known_At_Compile_Time (Typ)
5961 and then Tagged_Type_Expansion
5962 then
5963 Convert_To_Assignments (N, Typ);
5965 -- An aggregate used to initialize a controlled object must be turned
5966 -- into component assignments as the components themselves may require
5967 -- finalization actions such as adjustment.
5969 elsif Needs_Finalization (Typ) then
5970 Convert_To_Assignments (N, Typ);
5972 -- Ada 2005 (AI-287): In case of default initialized components we
5973 -- convert the aggregate into assignments.
5975 elsif Has_Default_Init_Comps (N) then
5976 Convert_To_Assignments (N, Typ);
5978 -- Check components
5980 elsif Component_Not_OK_For_Backend then
5981 Convert_To_Assignments (N, Typ);
5983 -- If an ancestor is private, some components are not inherited and we
5984 -- cannot expand into a record aggregate.
5986 elsif Has_Visible_Private_Ancestor (Typ) then
5987 Convert_To_Assignments (N, Typ);
5989 -- ??? The following was done to compile fxacc00.ads in the ACVCs. Gigi
5990 -- is not able to handle the aggregate for Late_Request.
5992 elsif Is_Tagged_Type (Typ) and then Has_Discriminants (Typ) then
5993 Convert_To_Assignments (N, Typ);
5995 -- If the tagged types covers interface types we need to initialize all
5996 -- hidden components containing pointers to secondary dispatch tables.
5998 elsif Is_Tagged_Type (Typ) and then Has_Interfaces (Typ) then
5999 Convert_To_Assignments (N, Typ);
6001 -- If some components are mutable, the size of the aggregate component
6002 -- may be distinct from the default size of the type component, so
6003 -- we need to expand to insure that the back-end copies the proper
6004 -- size of the data. However, if the aggregate is the initial value of
6005 -- a constant, the target is immutable and might be built statically
6006 -- if components are appropriate.
6008 elsif Has_Mutable_Components (Typ)
6009 and then
6010 (Nkind (Parent (Top_Level_Aggr)) /= N_Object_Declaration
6011 or else not Constant_Present (Parent (Top_Level_Aggr))
6012 or else not Static_Components)
6013 then
6014 Convert_To_Assignments (N, Typ);
6016 -- If the type involved has bit aligned components, then we are not sure
6017 -- that the back end can handle this case correctly.
6019 elsif Type_May_Have_Bit_Aligned_Components (Typ) then
6020 Convert_To_Assignments (N, Typ);
6022 -- In all other cases, build a proper aggregate to be handled by gigi
6024 else
6025 if Nkind (N) = N_Aggregate then
6027 -- If the aggregate is static and can be handled by the back-end,
6028 -- nothing left to do.
6030 if Static_Components then
6031 Set_Compile_Time_Known_Aggregate (N);
6032 Set_Expansion_Delayed (N, False);
6033 end if;
6034 end if;
6036 -- If no discriminants, nothing special to do
6038 if not Has_Discriminants (Typ) then
6039 null;
6041 -- Case of discriminants present
6043 elsif Is_Derived_Type (Typ) then
6045 -- For untagged types, non-stored discriminants are replaced
6046 -- with stored discriminants, which are the ones that gigi uses
6047 -- to describe the type and its components.
6049 Generate_Aggregate_For_Derived_Type : declare
6050 Constraints : constant List_Id := New_List;
6051 First_Comp : Node_Id;
6052 Discriminant : Entity_Id;
6053 Decl : Node_Id;
6054 Num_Disc : Int := 0;
6055 Num_Gird : Int := 0;
6057 procedure Prepend_Stored_Values (T : Entity_Id);
6058 -- Scan the list of stored discriminants of the type, and add
6059 -- their values to the aggregate being built.
6061 ---------------------------
6062 -- Prepend_Stored_Values --
6063 ---------------------------
6065 procedure Prepend_Stored_Values (T : Entity_Id) is
6066 begin
6067 Discriminant := First_Stored_Discriminant (T);
6068 while Present (Discriminant) loop
6069 New_Comp :=
6070 Make_Component_Association (Loc,
6071 Choices =>
6072 New_List (New_Occurrence_Of (Discriminant, Loc)),
6074 Expression =>
6075 New_Copy_Tree
6076 (Get_Discriminant_Value
6077 (Discriminant,
6078 Typ,
6079 Discriminant_Constraint (Typ))));
6081 if No (First_Comp) then
6082 Prepend_To (Component_Associations (N), New_Comp);
6083 else
6084 Insert_After (First_Comp, New_Comp);
6085 end if;
6087 First_Comp := New_Comp;
6088 Next_Stored_Discriminant (Discriminant);
6089 end loop;
6090 end Prepend_Stored_Values;
6092 -- Start of processing for Generate_Aggregate_For_Derived_Type
6094 begin
6095 -- Remove the associations for the discriminant of derived type
6097 First_Comp := First (Component_Associations (N));
6098 while Present (First_Comp) loop
6099 Comp := First_Comp;
6100 Next (First_Comp);
6102 if Ekind (Entity (First (Choices (Comp)))) = E_Discriminant
6103 then
6104 Remove (Comp);
6105 Num_Disc := Num_Disc + 1;
6106 end if;
6107 end loop;
6109 -- Insert stored discriminant associations in the correct
6110 -- order. If there are more stored discriminants than new
6111 -- discriminants, there is at least one new discriminant that
6112 -- constrains more than one of the stored discriminants. In
6113 -- this case we need to construct a proper subtype of the
6114 -- parent type, in order to supply values to all the
6115 -- components. Otherwise there is one-one correspondence
6116 -- between the constraints and the stored discriminants.
6118 First_Comp := Empty;
6120 Discriminant := First_Stored_Discriminant (Base_Type (Typ));
6121 while Present (Discriminant) loop
6122 Num_Gird := Num_Gird + 1;
6123 Next_Stored_Discriminant (Discriminant);
6124 end loop;
6126 -- Case of more stored discriminants than new discriminants
6128 if Num_Gird > Num_Disc then
6130 -- Create a proper subtype of the parent type, which is the
6131 -- proper implementation type for the aggregate, and convert
6132 -- it to the intended target type.
6134 Discriminant := First_Stored_Discriminant (Base_Type (Typ));
6135 while Present (Discriminant) loop
6136 New_Comp :=
6137 New_Copy_Tree
6138 (Get_Discriminant_Value
6139 (Discriminant,
6140 Typ,
6141 Discriminant_Constraint (Typ)));
6142 Append (New_Comp, Constraints);
6143 Next_Stored_Discriminant (Discriminant);
6144 end loop;
6146 Decl :=
6147 Make_Subtype_Declaration (Loc,
6148 Defining_Identifier => Make_Temporary (Loc, 'T'),
6149 Subtype_Indication =>
6150 Make_Subtype_Indication (Loc,
6151 Subtype_Mark =>
6152 New_Occurrence_Of (Etype (Base_Type (Typ)), Loc),
6153 Constraint =>
6154 Make_Index_Or_Discriminant_Constraint
6155 (Loc, Constraints)));
6157 Insert_Action (N, Decl);
6158 Prepend_Stored_Values (Base_Type (Typ));
6160 Set_Etype (N, Defining_Identifier (Decl));
6161 Set_Analyzed (N);
6163 Rewrite (N, Unchecked_Convert_To (Typ, N));
6164 Analyze (N);
6166 -- Case where we do not have fewer new discriminants than
6167 -- stored discriminants, so in this case we can simply use the
6168 -- stored discriminants of the subtype.
6170 else
6171 Prepend_Stored_Values (Typ);
6172 end if;
6173 end Generate_Aggregate_For_Derived_Type;
6174 end if;
6176 if Is_Tagged_Type (Typ) then
6178 -- In the tagged case, _parent and _tag component must be created
6180 -- Reset Null_Present unconditionally. Tagged records always have
6181 -- at least one field (the tag or the parent).
6183 Set_Null_Record_Present (N, False);
6185 -- When the current aggregate comes from the expansion of an
6186 -- extension aggregate, the parent expr is replaced by an
6187 -- aggregate formed by selected components of this expr.
6189 if Present (Parent_Expr) and then Is_Empty_List (Comps) then
6190 Comp := First_Component_Or_Discriminant (Typ);
6191 while Present (Comp) loop
6193 -- Skip all expander-generated components
6195 if not Comes_From_Source (Original_Record_Component (Comp))
6196 then
6197 null;
6199 else
6200 New_Comp :=
6201 Make_Selected_Component (Loc,
6202 Prefix =>
6203 Unchecked_Convert_To (Typ,
6204 Duplicate_Subexpr (Parent_Expr, True)),
6205 Selector_Name => New_Occurrence_Of (Comp, Loc));
6207 Append_To (Comps,
6208 Make_Component_Association (Loc,
6209 Choices =>
6210 New_List (New_Occurrence_Of (Comp, Loc)),
6211 Expression => New_Comp));
6213 Analyze_And_Resolve (New_Comp, Etype (Comp));
6214 end if;
6216 Next_Component_Or_Discriminant (Comp);
6217 end loop;
6218 end if;
6220 -- Compute the value for the Tag now, if the type is a root it
6221 -- will be included in the aggregate right away, otherwise it will
6222 -- be propagated to the parent aggregate.
6224 if Present (Orig_Tag) then
6225 Tag_Value := Orig_Tag;
6226 elsif not Tagged_Type_Expansion then
6227 Tag_Value := Empty;
6228 else
6229 Tag_Value :=
6230 New_Occurrence_Of
6231 (Node (First_Elmt (Access_Disp_Table (Typ))), Loc);
6232 end if;
6234 -- For a derived type, an aggregate for the parent is formed with
6235 -- all the inherited components.
6237 if Is_Derived_Type (Typ) then
6239 declare
6240 First_Comp : Node_Id;
6241 Parent_Comps : List_Id;
6242 Parent_Aggr : Node_Id;
6243 Parent_Name : Node_Id;
6245 begin
6246 -- Remove the inherited component association from the
6247 -- aggregate and store them in the parent aggregate
6249 First_Comp := First (Component_Associations (N));
6250 Parent_Comps := New_List;
6251 while Present (First_Comp)
6252 and then
6253 Scope (Original_Record_Component
6254 (Entity (First (Choices (First_Comp))))) /=
6255 Base_Typ
6256 loop
6257 Comp := First_Comp;
6258 Next (First_Comp);
6259 Remove (Comp);
6260 Append (Comp, Parent_Comps);
6261 end loop;
6263 Parent_Aggr :=
6264 Make_Aggregate (Loc,
6265 Component_Associations => Parent_Comps);
6266 Set_Etype (Parent_Aggr, Etype (Base_Type (Typ)));
6268 -- Find the _parent component
6270 Comp := First_Component (Typ);
6271 while Chars (Comp) /= Name_uParent loop
6272 Comp := Next_Component (Comp);
6273 end loop;
6275 Parent_Name := New_Occurrence_Of (Comp, Loc);
6277 -- Insert the parent aggregate
6279 Prepend_To (Component_Associations (N),
6280 Make_Component_Association (Loc,
6281 Choices => New_List (Parent_Name),
6282 Expression => Parent_Aggr));
6284 -- Expand recursively the parent propagating the right Tag
6286 Expand_Record_Aggregate
6287 (Parent_Aggr, Tag_Value, Parent_Expr);
6289 -- The ancestor part may be a nested aggregate that has
6290 -- delayed expansion: recheck now.
6292 if Component_Not_OK_For_Backend then
6293 Convert_To_Assignments (N, Typ);
6294 end if;
6295 end;
6297 -- For a root type, the tag component is added (unless compiling
6298 -- for the VMs, where tags are implicit).
6300 elsif Tagged_Type_Expansion then
6301 declare
6302 Tag_Name : constant Node_Id :=
6303 New_Occurrence_Of (First_Tag_Component (Typ), Loc);
6304 Typ_Tag : constant Entity_Id := RTE (RE_Tag);
6305 Conv_Node : constant Node_Id :=
6306 Unchecked_Convert_To (Typ_Tag, Tag_Value);
6308 begin
6309 Set_Etype (Conv_Node, Typ_Tag);
6310 Prepend_To (Component_Associations (N),
6311 Make_Component_Association (Loc,
6312 Choices => New_List (Tag_Name),
6313 Expression => Conv_Node));
6314 end;
6315 end if;
6316 end if;
6317 end if;
6319 end Expand_Record_Aggregate;
6321 ----------------------------
6322 -- Has_Default_Init_Comps --
6323 ----------------------------
6325 function Has_Default_Init_Comps (N : Node_Id) return Boolean is
6326 Comps : constant List_Id := Component_Associations (N);
6327 C : Node_Id;
6328 Expr : Node_Id;
6330 begin
6331 pragma Assert (Nkind_In (N, N_Aggregate, N_Extension_Aggregate));
6333 if No (Comps) then
6334 return False;
6335 end if;
6337 if Has_Self_Reference (N) then
6338 return True;
6339 end if;
6341 -- Check if any direct component has default initialized components
6343 C := First (Comps);
6344 while Present (C) loop
6345 if Box_Present (C) then
6346 return True;
6347 end if;
6349 Next (C);
6350 end loop;
6352 -- Recursive call in case of aggregate expression
6354 C := First (Comps);
6355 while Present (C) loop
6356 Expr := Expression (C);
6358 if Present (Expr)
6359 and then Nkind_In (Expr, N_Aggregate, N_Extension_Aggregate)
6360 and then Has_Default_Init_Comps (Expr)
6361 then
6362 return True;
6363 end if;
6365 Next (C);
6366 end loop;
6368 return False;
6369 end Has_Default_Init_Comps;
6371 --------------------------
6372 -- Is_Delayed_Aggregate --
6373 --------------------------
6375 function Is_Delayed_Aggregate (N : Node_Id) return Boolean is
6376 Node : Node_Id := N;
6377 Kind : Node_Kind := Nkind (Node);
6379 begin
6380 if Kind = N_Qualified_Expression then
6381 Node := Expression (Node);
6382 Kind := Nkind (Node);
6383 end if;
6385 if not Nkind_In (Kind, N_Aggregate, N_Extension_Aggregate) then
6386 return False;
6387 else
6388 return Expansion_Delayed (Node);
6389 end if;
6390 end Is_Delayed_Aggregate;
6392 ----------------------------------------
6393 -- Is_Static_Dispatch_Table_Aggregate --
6394 ----------------------------------------
6396 function Is_Static_Dispatch_Table_Aggregate (N : Node_Id) return Boolean is
6397 Typ : constant Entity_Id := Base_Type (Etype (N));
6399 begin
6400 return Static_Dispatch_Tables
6401 and then Tagged_Type_Expansion
6402 and then RTU_Loaded (Ada_Tags)
6404 -- Avoid circularity when rebuilding the compiler
6406 and then Cunit_Entity (Get_Source_Unit (N)) /= RTU_Entity (Ada_Tags)
6407 and then (Typ = RTE (RE_Dispatch_Table_Wrapper)
6408 or else
6409 Typ = RTE (RE_Address_Array)
6410 or else
6411 Typ = RTE (RE_Type_Specific_Data)
6412 or else
6413 Typ = RTE (RE_Tag_Table)
6414 or else
6415 (RTE_Available (RE_Interface_Data)
6416 and then Typ = RTE (RE_Interface_Data))
6417 or else
6418 (RTE_Available (RE_Interfaces_Array)
6419 and then Typ = RTE (RE_Interfaces_Array))
6420 or else
6421 (RTE_Available (RE_Interface_Data_Element)
6422 and then Typ = RTE (RE_Interface_Data_Element)));
6423 end Is_Static_Dispatch_Table_Aggregate;
6425 -----------------------------
6426 -- Is_Two_Dim_Packed_Array --
6427 -----------------------------
6429 function Is_Two_Dim_Packed_Array (Typ : Entity_Id) return Boolean is
6430 C : constant Int := UI_To_Int (Component_Size (Typ));
6431 begin
6432 return Number_Dimensions (Typ) = 2
6433 and then Is_Bit_Packed_Array (Typ)
6434 and then (C = 1 or else C = 2 or else C = 4);
6435 end Is_Two_Dim_Packed_Array;
6437 --------------------
6438 -- Late_Expansion --
6439 --------------------
6441 function Late_Expansion
6442 (N : Node_Id;
6443 Typ : Entity_Id;
6444 Target : Node_Id) return List_Id
6446 Aggr_Code : List_Id;
6448 begin
6449 if Is_Record_Type (Etype (N)) then
6450 Aggr_Code := Build_Record_Aggr_Code (N, Typ, Target);
6452 else pragma Assert (Is_Array_Type (Etype (N)));
6453 Aggr_Code :=
6454 Build_Array_Aggr_Code
6455 (N => N,
6456 Ctype => Component_Type (Etype (N)),
6457 Index => First_Index (Typ),
6458 Into => Target,
6459 Scalar_Comp => Is_Scalar_Type (Component_Type (Typ)),
6460 Indexes => No_List);
6461 end if;
6463 -- Save the last assignment statement associated with the aggregate
6464 -- when building a controlled object. This reference is utilized by
6465 -- the finalization machinery when marking an object as successfully
6466 -- initialized.
6468 if Needs_Finalization (Typ)
6469 and then Is_Entity_Name (Target)
6470 and then Present (Entity (Target))
6471 and then Ekind_In (Entity (Target), E_Constant, E_Variable)
6472 then
6473 Set_Last_Aggregate_Assignment (Entity (Target), Last (Aggr_Code));
6474 end if;
6476 return Aggr_Code;
6477 end Late_Expansion;
6479 ----------------------------------
6480 -- Make_OK_Assignment_Statement --
6481 ----------------------------------
6483 function Make_OK_Assignment_Statement
6484 (Sloc : Source_Ptr;
6485 Name : Node_Id;
6486 Expression : Node_Id) return Node_Id
6488 begin
6489 Set_Assignment_OK (Name);
6490 return Make_Assignment_Statement (Sloc, Name, Expression);
6491 end Make_OK_Assignment_Statement;
6493 -----------------------
6494 -- Number_Of_Choices --
6495 -----------------------
6497 function Number_Of_Choices (N : Node_Id) return Nat is
6498 Assoc : Node_Id;
6499 Choice : Node_Id;
6501 Nb_Choices : Nat := 0;
6503 begin
6504 if Present (Expressions (N)) then
6505 return 0;
6506 end if;
6508 Assoc := First (Component_Associations (N));
6509 while Present (Assoc) loop
6510 Choice := First (Choices (Assoc));
6511 while Present (Choice) loop
6512 if Nkind (Choice) /= N_Others_Choice then
6513 Nb_Choices := Nb_Choices + 1;
6514 end if;
6516 Next (Choice);
6517 end loop;
6519 Next (Assoc);
6520 end loop;
6522 return Nb_Choices;
6523 end Number_Of_Choices;
6525 ------------------------------------
6526 -- Packed_Array_Aggregate_Handled --
6527 ------------------------------------
6529 -- The current version of this procedure will handle at compile time
6530 -- any array aggregate that meets these conditions:
6532 -- One and two dimensional, bit packed
6533 -- Underlying packed type is modular type
6534 -- Bounds are within 32-bit Int range
6535 -- All bounds and values are static
6537 -- Note: for now, in the 2-D case, we only handle component sizes of
6538 -- 1, 2, 4 (cases where an integral number of elements occupies a byte).
6540 function Packed_Array_Aggregate_Handled (N : Node_Id) return Boolean is
6541 Loc : constant Source_Ptr := Sloc (N);
6542 Typ : constant Entity_Id := Etype (N);
6543 Ctyp : constant Entity_Id := Component_Type (Typ);
6545 Not_Handled : exception;
6546 -- Exception raised if this aggregate cannot be handled
6548 begin
6549 -- Handle one- or two dimensional bit packed array
6551 if not Is_Bit_Packed_Array (Typ)
6552 or else Number_Dimensions (Typ) > 2
6553 then
6554 return False;
6555 end if;
6557 -- If two-dimensional, check whether it can be folded, and transformed
6558 -- into a one-dimensional aggregate for the Packed_Array_Impl_Type of
6559 -- the original type.
6561 if Number_Dimensions (Typ) = 2 then
6562 return Two_Dim_Packed_Array_Handled (N);
6563 end if;
6565 if not Is_Modular_Integer_Type (Packed_Array_Impl_Type (Typ)) then
6566 return False;
6567 end if;
6569 if not Is_Scalar_Type (Component_Type (Typ))
6570 and then Has_Non_Standard_Rep (Component_Type (Typ))
6571 then
6572 return False;
6573 end if;
6575 declare
6576 Csiz : constant Nat := UI_To_Int (Component_Size (Typ));
6578 Lo : Node_Id;
6579 Hi : Node_Id;
6580 -- Bounds of index type
6582 Lob : Uint;
6583 Hib : Uint;
6584 -- Values of bounds if compile time known
6586 function Get_Component_Val (N : Node_Id) return Uint;
6587 -- Given a expression value N of the component type Ctyp, returns a
6588 -- value of Csiz (component size) bits representing this value. If
6589 -- the value is non-static or any other reason exists why the value
6590 -- cannot be returned, then Not_Handled is raised.
6592 -----------------------
6593 -- Get_Component_Val --
6594 -----------------------
6596 function Get_Component_Val (N : Node_Id) return Uint is
6597 Val : Uint;
6599 begin
6600 -- We have to analyze the expression here before doing any further
6601 -- processing here. The analysis of such expressions is deferred
6602 -- till expansion to prevent some problems of premature analysis.
6604 Analyze_And_Resolve (N, Ctyp);
6606 -- Must have a compile time value. String literals have to be
6607 -- converted into temporaries as well, because they cannot easily
6608 -- be converted into their bit representation.
6610 if not Compile_Time_Known_Value (N)
6611 or else Nkind (N) = N_String_Literal
6612 then
6613 raise Not_Handled;
6614 end if;
6616 Val := Expr_Rep_Value (N);
6618 -- Adjust for bias, and strip proper number of bits
6620 if Has_Biased_Representation (Ctyp) then
6621 Val := Val - Expr_Value (Type_Low_Bound (Ctyp));
6622 end if;
6624 return Val mod Uint_2 ** Csiz;
6625 end Get_Component_Val;
6627 -- Here we know we have a one dimensional bit packed array
6629 begin
6630 Get_Index_Bounds (First_Index (Typ), Lo, Hi);
6632 -- Cannot do anything if bounds are dynamic
6634 if not Compile_Time_Known_Value (Lo)
6635 or else
6636 not Compile_Time_Known_Value (Hi)
6637 then
6638 return False;
6639 end if;
6641 -- Or are silly out of range of int bounds
6643 Lob := Expr_Value (Lo);
6644 Hib := Expr_Value (Hi);
6646 if not UI_Is_In_Int_Range (Lob)
6647 or else
6648 not UI_Is_In_Int_Range (Hib)
6649 then
6650 return False;
6651 end if;
6653 -- At this stage we have a suitable aggregate for handling at compile
6654 -- time. The only remaining checks are that the values of expressions
6655 -- in the aggregate are compile-time known (checks are performed by
6656 -- Get_Component_Val), and that any subtypes or ranges are statically
6657 -- known.
6659 -- If the aggregate is not fully positional at this stage, then
6660 -- convert it to positional form. Either this will fail, in which
6661 -- case we can do nothing, or it will succeed, in which case we have
6662 -- succeeded in handling the aggregate and transforming it into a
6663 -- modular value, or it will stay an aggregate, in which case we
6664 -- have failed to create a packed value for it.
6666 if Present (Component_Associations (N)) then
6667 Convert_To_Positional
6668 (N, Max_Others_Replicate => 64, Handle_Bit_Packed => True);
6669 return Nkind (N) /= N_Aggregate;
6670 end if;
6672 -- Otherwise we are all positional, so convert to proper value
6674 declare
6675 Lov : constant Int := UI_To_Int (Lob);
6676 Hiv : constant Int := UI_To_Int (Hib);
6678 Len : constant Nat := Int'Max (0, Hiv - Lov + 1);
6679 -- The length of the array (number of elements)
6681 Aggregate_Val : Uint;
6682 -- Value of aggregate. The value is set in the low order bits of
6683 -- this value. For the little-endian case, the values are stored
6684 -- from low-order to high-order and for the big-endian case the
6685 -- values are stored from high-order to low-order. Note that gigi
6686 -- will take care of the conversions to left justify the value in
6687 -- the big endian case (because of left justified modular type
6688 -- processing), so we do not have to worry about that here.
6690 Lit : Node_Id;
6691 -- Integer literal for resulting constructed value
6693 Shift : Nat;
6694 -- Shift count from low order for next value
6696 Incr : Int;
6697 -- Shift increment for loop
6699 Expr : Node_Id;
6700 -- Next expression from positional parameters of aggregate
6702 Left_Justified : Boolean;
6703 -- Set True if we are filling the high order bits of the target
6704 -- value (i.e. the value is left justified).
6706 begin
6707 -- For little endian, we fill up the low order bits of the target
6708 -- value. For big endian we fill up the high order bits of the
6709 -- target value (which is a left justified modular value).
6711 Left_Justified := Bytes_Big_Endian;
6713 -- Switch justification if using -gnatd8
6715 if Debug_Flag_8 then
6716 Left_Justified := not Left_Justified;
6717 end if;
6719 -- Switch justfification if reverse storage order
6721 if Reverse_Storage_Order (Base_Type (Typ)) then
6722 Left_Justified := not Left_Justified;
6723 end if;
6725 if Left_Justified then
6726 Shift := Csiz * (Len - 1);
6727 Incr := -Csiz;
6728 else
6729 Shift := 0;
6730 Incr := +Csiz;
6731 end if;
6733 -- Loop to set the values
6735 if Len = 0 then
6736 Aggregate_Val := Uint_0;
6737 else
6738 Expr := First (Expressions (N));
6739 Aggregate_Val := Get_Component_Val (Expr) * Uint_2 ** Shift;
6741 for J in 2 .. Len loop
6742 Shift := Shift + Incr;
6743 Next (Expr);
6744 Aggregate_Val :=
6745 Aggregate_Val + Get_Component_Val (Expr) * Uint_2 ** Shift;
6746 end loop;
6747 end if;
6749 -- Now we can rewrite with the proper value
6751 Lit := Make_Integer_Literal (Loc, Intval => Aggregate_Val);
6752 Set_Print_In_Hex (Lit);
6754 -- Construct the expression using this literal. Note that it is
6755 -- important to qualify the literal with its proper modular type
6756 -- since universal integer does not have the required range and
6757 -- also this is a left justified modular type, which is important
6758 -- in the big-endian case.
6760 Rewrite (N,
6761 Unchecked_Convert_To (Typ,
6762 Make_Qualified_Expression (Loc,
6763 Subtype_Mark =>
6764 New_Occurrence_Of (Packed_Array_Impl_Type (Typ), Loc),
6765 Expression => Lit)));
6767 Analyze_And_Resolve (N, Typ);
6768 return True;
6769 end;
6770 end;
6772 exception
6773 when Not_Handled =>
6774 return False;
6775 end Packed_Array_Aggregate_Handled;
6777 ----------------------------
6778 -- Has_Mutable_Components --
6779 ----------------------------
6781 function Has_Mutable_Components (Typ : Entity_Id) return Boolean is
6782 Comp : Entity_Id;
6784 begin
6785 Comp := First_Component (Typ);
6786 while Present (Comp) loop
6787 if Is_Record_Type (Etype (Comp))
6788 and then Has_Discriminants (Etype (Comp))
6789 and then not Is_Constrained (Etype (Comp))
6790 then
6791 return True;
6792 end if;
6794 Next_Component (Comp);
6795 end loop;
6797 return False;
6798 end Has_Mutable_Components;
6800 ------------------------------
6801 -- Initialize_Discriminants --
6802 ------------------------------
6804 procedure Initialize_Discriminants (N : Node_Id; Typ : Entity_Id) is
6805 Loc : constant Source_Ptr := Sloc (N);
6806 Bas : constant Entity_Id := Base_Type (Typ);
6807 Par : constant Entity_Id := Etype (Bas);
6808 Decl : constant Node_Id := Parent (Par);
6809 Ref : Node_Id;
6811 begin
6812 if Is_Tagged_Type (Bas)
6813 and then Is_Derived_Type (Bas)
6814 and then Has_Discriminants (Par)
6815 and then Has_Discriminants (Bas)
6816 and then Number_Discriminants (Bas) /= Number_Discriminants (Par)
6817 and then Nkind (Decl) = N_Full_Type_Declaration
6818 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
6819 and then
6820 Present (Variant_Part (Component_List (Type_Definition (Decl))))
6821 and then Nkind (N) /= N_Extension_Aggregate
6822 then
6824 -- Call init proc to set discriminants.
6825 -- There should eventually be a special procedure for this ???
6827 Ref := New_Occurrence_Of (Defining_Identifier (N), Loc);
6828 Insert_Actions_After (N,
6829 Build_Initialization_Call (Sloc (N), Ref, Typ));
6830 end if;
6831 end Initialize_Discriminants;
6833 ----------------
6834 -- Must_Slide --
6835 ----------------
6837 function Must_Slide
6838 (Obj_Type : Entity_Id;
6839 Typ : Entity_Id) return Boolean
6841 L1, L2, H1, H2 : Node_Id;
6843 begin
6844 -- No sliding if the type of the object is not established yet, if it is
6845 -- an unconstrained type whose actual subtype comes from the aggregate,
6846 -- or if the two types are identical.
6848 if not Is_Array_Type (Obj_Type) then
6849 return False;
6851 elsif not Is_Constrained (Obj_Type) then
6852 return False;
6854 elsif Typ = Obj_Type then
6855 return False;
6857 else
6858 -- Sliding can only occur along the first dimension
6860 Get_Index_Bounds (First_Index (Typ), L1, H1);
6861 Get_Index_Bounds (First_Index (Obj_Type), L2, H2);
6863 if not Is_OK_Static_Expression (L1) or else
6864 not Is_OK_Static_Expression (L2) or else
6865 not Is_OK_Static_Expression (H1) or else
6866 not Is_OK_Static_Expression (H2)
6867 then
6868 return False;
6869 else
6870 return Expr_Value (L1) /= Expr_Value (L2)
6871 or else
6872 Expr_Value (H1) /= Expr_Value (H2);
6873 end if;
6874 end if;
6875 end Must_Slide;
6877 ----------------------------------
6878 -- Two_Dim_Packed_Array_Handled --
6879 ----------------------------------
6881 function Two_Dim_Packed_Array_Handled (N : Node_Id) return Boolean is
6882 Loc : constant Source_Ptr := Sloc (N);
6883 Typ : constant Entity_Id := Etype (N);
6884 Ctyp : constant Entity_Id := Component_Type (Typ);
6885 Comp_Size : constant Int := UI_To_Int (Component_Size (Typ));
6886 Packed_Array : constant Entity_Id :=
6887 Packed_Array_Impl_Type (Base_Type (Typ));
6889 One_Comp : Node_Id;
6890 -- Expression in original aggregate
6892 One_Dim : Node_Id;
6893 -- One-dimensional subaggregate
6895 begin
6897 -- For now, only deal with cases where an integral number of elements
6898 -- fit in a single byte. This includes the most common boolean case.
6900 if not (Comp_Size = 1 or else
6901 Comp_Size = 2 or else
6902 Comp_Size = 4)
6903 then
6904 return False;
6905 end if;
6907 Convert_To_Positional
6908 (N, Max_Others_Replicate => 64, Handle_Bit_Packed => True);
6910 -- Verify that all components are static
6912 if Nkind (N) = N_Aggregate
6913 and then Compile_Time_Known_Aggregate (N)
6914 then
6915 null;
6917 -- The aggregate may have been re-analyzed and converted already
6919 elsif Nkind (N) /= N_Aggregate then
6920 return True;
6922 -- If component associations remain, the aggregate is not static
6924 elsif Present (Component_Associations (N)) then
6925 return False;
6927 else
6928 One_Dim := First (Expressions (N));
6929 while Present (One_Dim) loop
6930 if Present (Component_Associations (One_Dim)) then
6931 return False;
6932 end if;
6934 One_Comp := First (Expressions (One_Dim));
6935 while Present (One_Comp) loop
6936 if not Is_OK_Static_Expression (One_Comp) then
6937 return False;
6938 end if;
6940 Next (One_Comp);
6941 end loop;
6943 Next (One_Dim);
6944 end loop;
6945 end if;
6947 -- Two-dimensional aggregate is now fully positional so pack one
6948 -- dimension to create a static one-dimensional array, and rewrite
6949 -- as an unchecked conversion to the original type.
6951 declare
6952 Byte_Size : constant Int := UI_To_Int (Component_Size (Packed_Array));
6953 -- The packed array type is a byte array
6955 Packed_Num : Int;
6956 -- Number of components accumulated in current byte
6958 Comps : List_Id;
6959 -- Assembled list of packed values for equivalent aggregate
6961 Comp_Val : Uint;
6962 -- integer value of component
6964 Incr : Int;
6965 -- Step size for packing
6967 Init_Shift : Int;
6968 -- Endian-dependent start position for packing
6970 Shift : Int;
6971 -- Current insertion position
6973 Val : Int;
6974 -- Component of packed array being assembled.
6976 begin
6977 Comps := New_List;
6978 Val := 0;
6979 Packed_Num := 0;
6981 -- Account for endianness. See corresponding comment in
6982 -- Packed_Array_Aggregate_Handled concerning the following.
6984 if Bytes_Big_Endian
6985 xor Debug_Flag_8
6986 xor Reverse_Storage_Order (Base_Type (Typ))
6987 then
6988 Init_Shift := Byte_Size - Comp_Size;
6989 Incr := -Comp_Size;
6990 else
6991 Init_Shift := 0;
6992 Incr := +Comp_Size;
6993 end if;
6995 -- Iterate over each subaggregate
6997 Shift := Init_Shift;
6998 One_Dim := First (Expressions (N));
6999 while Present (One_Dim) loop
7000 One_Comp := First (Expressions (One_Dim));
7001 while Present (One_Comp) loop
7002 if Packed_Num = Byte_Size / Comp_Size then
7004 -- Byte is complete, add to list of expressions
7006 Append (Make_Integer_Literal (Sloc (One_Dim), Val), Comps);
7007 Val := 0;
7008 Shift := Init_Shift;
7009 Packed_Num := 0;
7011 else
7012 Comp_Val := Expr_Rep_Value (One_Comp);
7014 -- Adjust for bias, and strip proper number of bits
7016 if Has_Biased_Representation (Ctyp) then
7017 Comp_Val := Comp_Val - Expr_Value (Type_Low_Bound (Ctyp));
7018 end if;
7020 Comp_Val := Comp_Val mod Uint_2 ** Comp_Size;
7021 Val := UI_To_Int (Val + Comp_Val * Uint_2 ** Shift);
7022 Shift := Shift + Incr;
7023 One_Comp := Next (One_Comp);
7024 Packed_Num := Packed_Num + 1;
7025 end if;
7026 end loop;
7028 One_Dim := Next (One_Dim);
7029 end loop;
7031 if Packed_Num > 0 then
7033 -- Add final incomplete byte if present
7035 Append (Make_Integer_Literal (Sloc (One_Dim), Val), Comps);
7036 end if;
7038 Rewrite (N,
7039 Unchecked_Convert_To (Typ,
7040 Make_Qualified_Expression (Loc,
7041 Subtype_Mark => New_Occurrence_Of (Packed_Array, Loc),
7042 Expression => Make_Aggregate (Loc, Expressions => Comps))));
7043 Analyze_And_Resolve (N);
7044 return True;
7045 end;
7046 end Two_Dim_Packed_Array_Handled;
7048 ---------------------
7049 -- Sort_Case_Table --
7050 ---------------------
7052 procedure Sort_Case_Table (Case_Table : in out Case_Table_Type) is
7053 L : constant Int := Case_Table'First;
7054 U : constant Int := Case_Table'Last;
7055 K : Int;
7056 J : Int;
7057 T : Case_Bounds;
7059 begin
7060 K := L;
7061 while K /= U loop
7062 T := Case_Table (K + 1);
7064 J := K + 1;
7065 while J /= L
7066 and then Expr_Value (Case_Table (J - 1).Choice_Lo) >
7067 Expr_Value (T.Choice_Lo)
7068 loop
7069 Case_Table (J) := Case_Table (J - 1);
7070 J := J - 1;
7071 end loop;
7073 Case_Table (J) := T;
7074 K := K + 1;
7075 end loop;
7076 end Sort_Case_Table;
7078 ----------------------------
7079 -- Static_Array_Aggregate --
7080 ----------------------------
7082 function Static_Array_Aggregate (N : Node_Id) return Boolean is
7083 Bounds : constant Node_Id := Aggregate_Bounds (N);
7085 Typ : constant Entity_Id := Etype (N);
7086 Comp_Type : constant Entity_Id := Component_Type (Typ);
7087 Agg : Node_Id;
7088 Expr : Node_Id;
7089 Lo : Node_Id;
7090 Hi : Node_Id;
7092 begin
7093 if Is_Tagged_Type (Typ)
7094 or else Is_Controlled (Typ)
7095 or else Is_Packed (Typ)
7096 then
7097 return False;
7098 end if;
7100 if Present (Bounds)
7101 and then Nkind (Bounds) = N_Range
7102 and then Nkind (Low_Bound (Bounds)) = N_Integer_Literal
7103 and then Nkind (High_Bound (Bounds)) = N_Integer_Literal
7104 then
7105 Lo := Low_Bound (Bounds);
7106 Hi := High_Bound (Bounds);
7108 if No (Component_Associations (N)) then
7110 -- Verify that all components are static integers
7112 Expr := First (Expressions (N));
7113 while Present (Expr) loop
7114 if Nkind (Expr) /= N_Integer_Literal then
7115 return False;
7116 end if;
7118 Next (Expr);
7119 end loop;
7121 return True;
7123 else
7124 -- We allow only a single named association, either a static
7125 -- range or an others_clause, with a static expression.
7127 Expr := First (Component_Associations (N));
7129 if Present (Expressions (N)) then
7130 return False;
7132 elsif Present (Next (Expr)) then
7133 return False;
7135 elsif Present (Next (First (Choices (Expr)))) then
7136 return False;
7138 else
7139 -- The aggregate is static if all components are literals,
7140 -- or else all its components are static aggregates for the
7141 -- component type. We also limit the size of a static aggregate
7142 -- to prevent runaway static expressions.
7144 if Is_Array_Type (Comp_Type)
7145 or else Is_Record_Type (Comp_Type)
7146 then
7147 if Nkind (Expression (Expr)) /= N_Aggregate
7148 or else
7149 not Compile_Time_Known_Aggregate (Expression (Expr))
7150 then
7151 return False;
7152 end if;
7154 elsif Nkind (Expression (Expr)) /= N_Integer_Literal then
7155 return False;
7156 end if;
7158 if not Aggr_Size_OK (N, Typ) then
7159 return False;
7160 end if;
7162 -- Create a positional aggregate with the right number of
7163 -- copies of the expression.
7165 Agg := Make_Aggregate (Sloc (N), New_List, No_List);
7167 for I in UI_To_Int (Intval (Lo)) .. UI_To_Int (Intval (Hi))
7168 loop
7169 Append_To (Expressions (Agg), New_Copy (Expression (Expr)));
7171 -- The copied expression must be analyzed and resolved.
7172 -- Besides setting the type, this ensures that static
7173 -- expressions are appropriately marked as such.
7175 Analyze_And_Resolve
7176 (Last (Expressions (Agg)), Component_Type (Typ));
7177 end loop;
7179 Set_Aggregate_Bounds (Agg, Bounds);
7180 Set_Etype (Agg, Typ);
7181 Set_Analyzed (Agg);
7182 Rewrite (N, Agg);
7183 Set_Compile_Time_Known_Aggregate (N);
7185 return True;
7186 end if;
7187 end if;
7189 else
7190 return False;
7191 end if;
7192 end Static_Array_Aggregate;
7194 end Exp_Aggr;